1125:) in Resolution 3 first considered using the triple point of water as a defining point, the triple point was so close to being 0.01 °C greater than water's known melting point, it was simply defined as precisely 0.01 °C. However, later measurements showed that the difference between the triple and melting points of VSMOW is actually very slightly (< 0.001 °C) greater than 0.01 °C. Thus, the actual melting point of ice is very slightly (less than a thousandth of a degree) below 0 °C. Also, defining water's triple point at 273.16 K precisely defined the magnitude of each 1 °C increment in terms of the
495:
848:: differences between temperatures or their uncertainties (e.g. "The output of the heat exchanger is hotter by 40 degrees Celsius", and "Our standard uncertainty is ±3 °C"). Because of this dual usage, one must not rely upon the unit name or its symbol to denote that a quantity is a temperature interval; it must be unambiguous through context or explicit statement that the quantity is an interval. This is sometimes solved by using the symbol °C (pronounced "degrees Celsius") for a temperature, and C° (pronounced "Celsius degrees") for a temperature interval, although this usage is non-standard. Another way to express the same is
405:(1707–1778) reversed Celsius's scale. His custom-made "Linnaeus-thermometer", for use in his greenhouses, was made by Daniel Ekström, Sweden's leading maker of scientific instruments at the time, whose workshop was located in the basement of the Stockholm observatory. As often happened in this age before modern communications, numerous physicists, scientists, and instrument makers are credited with having independently developed this same scale; among them were Pehr Elvius, the secretary of the Royal Swedish Academy of Sciences (which had an instrument workshop) and with whom Linnaeus had been corresponding;
341:
1211:(OED), the term "Celsius thermometer" had been used at least as early as 1797. Further, the term "The Celsius or Centigrade thermometer" was again used in reference to a particular type of thermometer at least as early as 1850. The OED also cites this 1928 reporting of a temperature: "My altitude was about 5,800 metres, the temperature was 28° Celsius." However, dictionaries seek to find the earliest use of a word or term and are not a useful resource as regards to the terminology used throughout the history of science. According to several writings of
310:
2166:
2662:
2688:
359:, he recounted his experiments showing that the melting point of ice is essentially unaffected by pressure. He also determined with remarkable precision how the boiling point of water varied as a function of atmospheric pressure. He proposed that the zero point of his temperature scale, being the boiling point, would be calibrated at the mean barometric pressure at mean sea level. This pressure is known as one
1306:(101.325 kPa) when calibrated solely per the two-point definition of thermodynamic temperature. Older definitions of the Celsius temperature scale once defined the boiling point of water under one standard atmosphere as being precisely 100 °C. However, the current definition results in a boiling point that is actually 16.1 mK less. For more about the actual boiling point of water, see
53:
863:; and it follows a relative scale not an absolute scale. For example, an object at 20 °C does not have twice the energy of when it is 10 °C; and 0 °C is not the lowest Celsius value. Thus, degrees Celsius is a useful interval measurement but does not possess the characteristics of ratio measures like weight or distance.
394:, inverted the Celsius temperature scale so that 0 represented the freezing point of water and 100 represented the boiling point of water. Some credit Christin for independently inventing the reverse of Celsius's original scale, while others believe Christin merely reversed Celsius's scale. On 19 May 1743 he published the design of a
1340:
the quantity. Thus, if a temperature interval is, say, 10 K or 10 °C (which may be written 10 kelvins or 10 degrees
Celsius), it must be unambiguous through obvious context or explicit statement that the quantity is an interval. Rules governing the expressing of temperatures and intervals are covered in the BIPM's
1159:
This boiling-point difference of 16.1 millikelvins between the
Celsius temperature scale's original definition and the previous one (based on absolute zero and the triple point) has little practical meaning in common daily applications because water's boiling point is very sensitive to variations in
1256:
in connection with the centigrade scale was not used whatsoever by the scientific or thermometry communities until after the CIPM and CGPM adopted the term in 1948. The BIPM was not even aware that "degree
Celsius" was in sporadic, non-scientific use before that time. It is also noteworthy that the
428:
since the caldarium (the hot part of the greenhouse) by the angle of the windows, merely from the rays of the sun, obtains such heat that the thermometer often reaches 30 degrees, although the keen gardener usually takes care not to let it rise to more than 20 to 25 degrees, and in winter not under
1339:
Consequently, there is now wide freedom in usage regarding how to indicate a temperature interval. The most important thing is that one's intention must be clear and the basic rule of the SI must be followed; namely that the unit name or its symbol must not be relied upon to indicate the nature of
872:
Notwithstanding the official endorsement provided by decision no. 3 of
Resolution 3 of the 13th CGPM, which stated "a temperature interval may also be expressed in degrees Celsius", the practice of simultaneously using both °C and K remains widespread throughout the scientific world as the use of
871:
In science and in engineering, the
Celsius and Kelvin scales are often used in combination in close contexts, e.g. "a measured value was 0.01023 °C with an uncertainty of 70 μK". This practice is permissible because the magnitude of the degree Celsius is equal to that of the kelvin.
792:
with legacy encodings. It easily allows correct rendering for vertically written East Asian scripts, such as
Chinese. The Unicode standard explicitly discourages the use of this character: "In normal use, it is better to represent degrees Celsius '°C' with a sequence of
466:
was later introduced for temperatures but was also problematic, as it means gradian (one hundredth of a right angle) in the French and
Spanish languages. The risk of confusion between temperature and angular measurement was eliminated in 1948 when the 9th meeting of the
1279:
Notwithstanding the important contribution of
Linnaeus who gave the Celsius temperature scale its modern form, Celsius's name was the obvious choice because it began with the letter C. Thus, the symbol °C that for centuries had been used in association with the name
474:
While "Celsius" is commonly used in scientific work, "centigrade" is still used in French and
English-speaking countries, especially in informal contexts. The frequency of the usage of "centigrade" has declined over time.
446:
communities worldwide have used the phrase "centigrade scale" and temperatures were often reported simply as "degrees" or, when greater specificity was desired, as "degrees centigrade", with the symbol °C.
355:(1701–1744) created a temperature scale that was the reverse of the scale now known as "Celsius": 0 represented the boiling point of water, while 100 represented the freezing point of water. In his paper
1386:"Celsius temperature scale, also called centigrade temperature scale, scale based on 0 ° for the melting point of water and 100 ° for the boiling point of water at 1 atm pressure."
1337:...and the designation of the unit to express an interval or a difference of temperatures are abrogated, but the usages which derive from these decisions remain permissible for the time being."
760:, and ″, respectively), for which no space is left between the numerical value and the unit symbol. Other languages, and various publishing houses, may follow different typographical rules.
1427:
840:
The degree
Celsius is subject to the same rules as the kelvin with regard to the use of its unit name and symbol. Thus, besides expressing specific temperatures along its scale (e.g. "
1156:(a calibration standard comprising many definition points and commonly used for high-precision instrumentation), the boiling point of VSMOW was slightly less, about 99.974 °C.
1152:
to the two-point definition for calibration, the boiling point of VSMOW under one standard atmosphere of pressure was actually 373.1339 K (99.9839 °C). When calibrated to
1129:(referencing absolute zero). Now decoupled from the actual boiling point of water, the value "100 °C" is hotter than 0 °C – in absolute terms – by a factor of
1699:
1111:. Each of these formal definitions left the numerical values of the Celsius temperature scale identical to the prior definition to within the limits of accuracy of the
482:, after 1 September 1972 weather reports in the country were exclusively given in Celsius. In the United Kingdom, it was not until February 1985 that forecasts by
1118:
When the melting and boiling points of water ceased being part of the definition, they became measured quantities instead. This is also true of the triple point.
1287:
The new name eliminated the ambiguity of the term "centigrade", freeing it to refer exclusively to the French-language name for the unit of angular measurement.
1276:
All common temperature scales would have their units named after someone closely associated with them; namely, Kelvin, Celsius, Fahrenheit, Réaumur and Rankine.
240:) can refer to a specific point on the Celsius temperature scale or to a difference or range between two temperatures. It is named after the Swedish astronomer
1095:
The melting and boiling points of water are no longer part of the definition of the Celsius temperature scale. In 1948, the definition was changed to use the
2322:
1405:
406:
275:
Throughout the 19th century, the scale was based on 0 °C for the freezing point of water and 100 °C for the boiling point of water at 1
416:
dated 16 December 1745 that Linnaeus wrote to a student of his, Samuel Nauclér. In it, Linnaeus recounted the temperatures inside the orangery at the
1307:
1217:
2204:
1449:
257:
2233:
1329:"To indicate a temperature interval or difference, rather than a temperature, the word 'degree' in full, or the abbreviation 'deg' must be used."
2009:
844:
melts at 29.7646 °C" and "The temperature outside is 23 degrees Celsius"), the degree Celsius is also suitable for expressing temperature
2021:
1988:
1866:
279:
pressure. (In Celsius's initial proposal, the values were reversed: the boiling point was 0 degrees and the freezing point was 100 degrees.)
2128:
1750:
1453:
745:
364:
2637:
468:
368:
876:
forms of the degree Celsius (such as "μ°C" or "microdegrees Celsius") to express a temperature interval has not been widely adopted.
1746:
1153:
1683:
1801:
1719:
417:
748:(BIPM) is that the numerical value always precedes the unit, and a space is always used to separate the unit from the number,
2052:
1573:
1544:
1173:
1954:
2318:
2226:
1164:. For example, an altitude change of only 28 cm (11 in) causes the boiling point to change by one millikelvin.
1086:
412:
The first known Swedish document reporting temperatures in this modern "forward" Celsius temperature scale is the paper
2353:
2728:
2543:
1299:
1178:
785:
2087:
H.D. Young, R. A. Freedman (2008). University Physics with Modern Physics (12th ed.). Addison Wesley. p. 573.
347:'s original thermometer used a reversed scale, with 100 as the freezing point and 0 as the boiling point of water.
2733:
2713:
2647:
2219:
1480:
629:
72:
2362:
1397:
673:
229:
471:
and the Comité International des Poids et Mesures (CIPM) formally adopted "degree Celsius" for temperature.
1721:
Comptes rendus des séances de la cinquième conférence générale des poids et mesures, réunie à Paris en 1913
789:
2723:
2718:
1224:
35:
1488:
1457:
1099:. In 2005, the definition was further refined to use water with precisely defined isotopic composition (
2678:
1831:
1671:; citation for Linnaeus's connection with Pehr Elvius and Daniel Ekström: Uppsala University (Sweden),
1485:
Kungliga Svenska Vetenskapsakademiens Handlingar (Proceedings of the Royal Swedish Academy of Sciences)
503:
409:, the instrument maker; and Mårten Strömer (1707–1770) who had studied astronomy under Anders Celsius.
17:
1580:
1743 Jean-Pierre Christin inverts the fixed points on Celsius' scale, to produce the scale used today.
1382:
2708:
1906:
1501:
Resolution 4 of the 10th meeting of the CGPM - Definition of the standard atmosphere (Report). 1954.
1188:
1126:
299:
2601:
479:
31:
2110:
2018:
1881:
2642:
2124:
873:
287:
1284:
could remain in use and would simultaneously inherit an intuitive association with the new name.
2346:
1637:
1592:
1561:
260:
renamed it to honor Celsius and also to remove confusion with the term for one hundredth of a
1534:
1096:
1615:
1342:
2242:
387:
225:
2149:
494:
340:
8:
2627:
2039:
1161:
459:
395:
1754:
1108:
1104:
398:, the "Thermometer of Lyon" built by the craftsman Pierre Casati that used this scale.
306:, the lowest temperature, is now defined as being exactly 0 K and −273.15 °C.
169:
1825:
2665:
2551:
2339:
2048:
1959:
The NIST Reference on Constants, Units, and Uncertainty: Historical context of the SI
1929:
1678:
1597:
1569:
1540:
1303:
498:
Equivalent temperatures in kelvin (K), Rankine (R), Celsius (°C), and Fahrenheit (°F)
360:
290:
of water. Since 2007, the Celsius temperature scale has been defined in terms of the
276:
2188:
1377:
752:(not "30.2°C" or "30.2° C"). The only exceptions to this rule are for the unit
2004:
2002:
For more information on conventions used in technical writing, see the informative
1672:
1652:
1510:
1502:
653:
2297:
1705:
2418:
2025:
1687:
1183:
593:
506:. Figures are either by definition, or approximated from empirical measurements.
391:
2180:
2170:
2571:
2503:
2307:
1966:
1666:
1601:(in French). Paris: Chaubert; Jean de Nully, Pissot, Duchesne: 1609–1610. 1743.
856:
352:
344:
244:(1701–1744), who proposed the first version of it in 1742. The unit was called
241:
165:
103:
2302:
2702:
2692:
2632:
2556:
2493:
2483:
2292:
2262:
1867:"Reproducibility of the Temperature of the Ice Point in Routine Measurements"
1539:. Facts on File Science Dictionary. Facts On File, Incorporated. p. 43.
1212:
986:
753:
530:
402:
309:
303:
155:
140:
1515:
371:(CGPM) in 1954 defined one standard atmosphere to equal precisely 1,013,250
2576:
2533:
2518:
2473:
2453:
2370:
2287:
2282:
1506:
1257:
twelve-volume, 1933 edition of OED didn't even have a listing for the word
1218:"Temperature Scales from the early days of thermometry to the 21st century"
730:
401:
In 1744, coincident with the death of Anders Celsius, the Swedish botanist
295:
233:
1621:
2448:
2403:
2246:
1530:
483:
443:
213:
58:
2211:
2196:
2165:
2267:
1103:) for the triple point. In 2019, the definition was changed to use the
900:
860:
729:
whose full unit name contains an uppercase letter since 1967, when the
555:
525:
268:
scale is still used in the United States, some island territories, and
265:
2075:
1724:. Bureau international des poids et mesures. 1913. pp. 55, 57, 59
1332:
2513:
2428:
1324:
1112:
437:
2393:
2272:
1353:
1243:
61:
calibrated in degrees Celsius, showing a temperature of −17 °C
1483:[Observations about two stable degrees on a thermometer].
2687:
2581:
2566:
2508:
2433:
2383:
1269:
in the context of temperature measurement). The 1948 adoption of
1121:
In 1948 when the 9th General Conference on Weights and Measures (
841:
768:
726:
633:
455:
269:
261:
1645:
2596:
2498:
2408:
2388:
2378:
2277:
2206:
SI brochure, section 2.1.1.5, Unit of thermodynamic temperature
1311:
1148:(approximately 36.61% thermodynamically hotter). When adhering
959:
734:
517:
291:
1107:, completely decoupling the definition of the kelvin from the
2611:
2606:
2591:
2468:
2463:
2458:
2443:
2398:
2047:. Mountain View, CA, USA: The Unicode Consortium. July 2016.
1481:"Observationer om twänne beständiga grader på en thermometer"
1100:
286:
and the Celsius temperature scale used absolute zero and the
713:
NIST common reference temperature, provided as round numbers
200:
2586:
2528:
2523:
2331:
2013:
1962:
1122:
383:
372:
282:
Between 1954 and 2019, the precise definitions of the unit
52:
1692:
1677:; general citation: The Uppsala Astronomical Observatory,
1593:"MEMOIRE sur la dilatation du Mercure dans le Thermométre"
832:. For searching, treat these two sequences as identical."
2561:
2488:
2478:
2098:
Biostatistics: A Guide to Design, Analysis, and Discovery
376:
1398:"What Is the Difference Between Celsius and Centigrade?"
1634:
Memoires pour L'Histoire des Sciences et des Beaux Arts
1252:(2nd Edition/1990/Academic Press/0125696817), the term
357:
Observations of two persistent degrees on a thermometer
77:
2100:
By Ronald N. Forthofer, Eun Sul Lee and Mike Hernandez
1807:. Commonwealth Bureau of Meteorology. 1 September 1972
1314:, which approximates the temperature to 99.974 °C
879:
264:
in some languages. Most countries use this scale (the
2676:
1996:
1963:
National Institute of Standards and Technology (NIST)
1855:
The ice point of purified water has been measured at
1776:
1930:"Temperature of a Healthy Human (Body Temperature)"
1836:
1566:
The Facts on File Dictionary of Weather and Climate
1665:Citation for Christin of Lyons: Le Moyne College,
1428:"Proceedings of the 42nd CIPM (1948), 1948, p. 88"
256:, which means steps) for many years. In 1948, the
1430:. Bureau International des Poids et Mesures. 1948
30:"Centigrade" redirects here. For other uses, see
2700:
1659:
258:International Committee for Weights and Measures
1331:This resolution was abrogated in 1967/1968 by
1215:, Director of the BIPM (1988–2004), including
720:
2347:
2227:
2151:Water Structure and Behavior, notes c1 and c2
1849:
1739:
1529:
852:, which can be commonly found in literature.
835:
2129:International Bureau of Weights and Measures
1955:"Unit of thermodynamic temperature (kelvin)"
1819:
1751:International Bureau of Weights and Measures
1698:Citations: University of Wisconsin–Madison,
1627:
1454:International Bureau of Weights and Measures
1396:Helmenstine, Anne Marie (15 December 2014).
746:International Bureau of Weights and Measures
700:
698:
2638:Historical definitions of the SI base units
1909:. NIST Office of Weights and Measures. 2010
1395:
704:Exact value, by SI definition of the kelvin
442:Since the 19th century, the scientific and
2354:
2340:
2234:
2220:
2090:
1585:
1553:
1442:
866:
771:provides the Celsius symbol at code point
469:General Conference on Weights and Measures
369:General Conference on Weights and Measures
232:(SI), the other being the closely related
51:
2241:
1921:
1827:1985 BBC Special: A Change In The Weather
1514:
756:, minute, and second for plane angle (°,
695:
486:switched from "centigrade" to "Celsius".
2190:History of the Celsius temperature scale
2148:Citation: London South Bank University,
2117:
1899:
1680:History of the Celsius temperature scale
1127:absolute thermodynamic temperature scale
885:Celsius temperature conversion formulae
741:. The plural form is "degrees Celsius".
493:
339:
308:
2081:
1651:Citation: Uppsala University (Sweden),
1478:
1292:
725:The "degree Celsius" has been the only
707:
14:
2701:
2187:The Uppsala Astronomical Observatory,
2142:
2111:"Resolution 3 of the 13th CGPM (1967)"
2096:This fact is demonstrated in the book
2068:
1864:
1734:...à la température de 20° centésimaux
1317:
489:
418:University of Uppsala Botanical Garden
324: Celsius (°C) and Fahrenheit (°F)
2335:
2215:
2125:"Resolution 3 of the 9th CGPM (1948)"
1947:
1927:
1769:
1712:
1605:
1559:
1494:
1408:from the original on 27 November 2023
1087:Conversion between temperature scales
248:in several languages (from the Latin
1802:"Temperature and Pressure go Metric"
1568:. Infobase Publishing. p. 246.
1523:
1174:Outline of metrology and measurement
763:
375:per square centimeter (101.325
2019:Formatting the value of a quantity.
2005:SI Unit rules and style conventions
1201:
880:Melting and boiling points of water
27:Unit of measurement for temperature
24:
2016:'s SI brochure: Subsection 5.3.3,
1844:Handbook of Chemistry and Physics.
1371:
1049:rather than specific temperatures,
25:
2745:
2159:
2041:The Unicode Standard, Version 9.0
1310:. A different approximation uses
1024: − 491.67) ×
998: + 273.15) ×
737:, replacing the capitalized term
450:In the French language, the term
2686:
2661:
2660:
2164:
1308:VSMOW in temperature measurement
1300:Vienna Standard Mean Ocean Water
1261:(but did have listings for both
1179:Comparison of temperature scales
510:Key temperature scale relations
2103:
2031:
1981:
1794:
1747:"CIPM, 1948 and 9th CGPM, 1948"
1642:Chaubert, París. pp. 2125–2128.
1273:accomplished three objectives:
855:Celsius measurement follows an
2648:System of units of measurement
2195:London South Bank University,
2182:Basic unit definitions: Kelvin
1472:
1450:"SI brochure, section 2.1.1.5"
1420:
1389:
454:also means one hundredth of a
236:. The degree Celsius (symbol:
13:
1:
2169:The dictionary definition of
2076:Resolution 3 of the 13th CGPM
1842:Lide, D.R., ed. (1990–1991).
1620:Imprimerie des Journalistes,
1365:
1333:Resolution 3 of the 13th CGPM
1209:The Oxford English Dictionary
981: − 273.15) °C
938: − 32) ×
674:normal human body temperature
502:All phase transitions are at
438:"Centigrade" versus "Celsius"
390:, permanent secretary of the
230:International System of Units
2361:
1846:71st ed. CRC Press. p. 4–22.
1325:Resolution 7 of the 9th CGPM
971: + 273.15) K
554:Intersection of Celsius and
351:In 1742, Swedish astronomer
224:outside Sweden), one of two
7:
1167:
985:
958:
899:
733:for temperature became the
721:Name and symbol typesetting
36:Centigrade (disambiguation)
10:
2750:
1865:Magnum, B.W. (June 1995).
1560:Smith, Jacqueline (2009).
1343:"SI Brochure, 8th edition"
836:Temperatures and intervals
335:
29:
2656:
2620:
2542:
2417:
2369:
2316:
2253:
1782:. Oxford University Press
1780:Oxford English Dictionary
1777:"centigrade, adj. and n."
1704:and; Uppsala University,
1668:Glossary, (Celsius scale)
1536:Encyclopedia of Chemistry
1378:Celsius temperature scale
1189:Thermodynamic temperature
1044:
928: + 32) °F
300:thermodynamic temperature
220:(originally known as the
218:Celsius temperature scale
161:
136:
132:
109:
99:
91:
83:
71:
66:
50:
45:
2602:minute and second of arc
1907:"SI Units – Temperature"
1701:Linnæus & his Garden
1562:"Appendix I: Chronology"
1479:Celsius, Anders (1742).
1194:
744:The general rule of the
480:metrication in Australia
32:Celsius (disambiguation)
2729:18th-century inventions
2643:2019 revision of the SI
1533:; Bailey, R.A. (2014).
1383:Encyclopædia Britannica
1051:1 °C = 1 K =
867:Coexistence with Kelvin
790:roundtrip compatibility
786:compatibility character
575:Boiling point of water
252:, which means 100, and
2198:Water, scientific data
1965:. 2000. Archived from
1863:degrees Celsius – see
1507:10.59161/CGPM1954RES4E
1020: °R ≘ (
994: °C ≘ (
967: °C ≘ (
934: °F ≘ (
908: °C ≘ (
817:LATIN CAPITAL LETTER C
499:
435:
348:
332:
127:... corresponds to ...
2734:Scales in meteorology
2714:Scales of temperature
1928:Elert, Glenn (2005).
1707:Linnaeus' thermometer
1674:Linnaeus' thermometer
1654:Linnaeus' thermometer
1097:triple point of water
977: K ≘ (
784:. However, this is a
612:Melting point of ice
497:
422:
343:
330: Fahrenheit (°F)
312:
2544:Other accepted units
1934:The Physics Factbook
1686:22 July 2009 at the
1460:on 26 September 2007
1335:, which stated that
388:Jean-Pierre Christin
2628:Conversion of units
2319:Conversion formulas
2024:5 July 2014 at the
1969:on 11 November 2004
1874:NIST Technical Note
1304:standard atmosphere
1230:on 26 December 2010
1162:barometric pressure
1109:properties of water
886:
511:
504:standard atmosphere
490:Common temperatures
460:angular measurement
396:mercury thermometer
361:standard atmosphere
67:General information
2724:1742 introductions
2719:Swedish inventions
2421:with special names
2074:Decision No. 3 of
1612:Journal helvétique
1105:Boltzmann constant
884:
754:symbols for degree
509:
500:
414:Hortus Upsaliensis
349:
333:
318: Celsius (°C)
313:Countries by usage
226:temperature scales
176:
163:
146:
138:
2674:
2673:
2552:astronomical unit
2329:
2328:
2054:978-1-936213-13-9
1598:Mercure de France
1575:978-1-4381-0951-0
1546:978-1-4381-1002-8
1487:(3): 171–180 and
1093:
1092:
1089:
764:Unicode character
691:
690:
624:491.6698 °R
592:Boiling point of
587:671.6410 °R
464:centesimal degree
206:
205:
110:Conversions
16:(Redirected from
2741:
2709:SI derived units
2691:
2690:
2682:
2664:
2663:
2356:
2349:
2342:
2333:
2332:
2236:
2229:
2222:
2213:
2212:
2168:
2154:
2146:
2140:
2139:
2137:
2135:
2121:
2115:
2114:
2107:
2101:
2094:
2088:
2085:
2079:
2072:
2066:
2065:
2063:
2061:
2046:
2035:
2029:
2000:
1994:
1992:, Section 5.3.3.
1985:
1979:
1978:
1976:
1974:
1951:
1945:
1944:
1942:
1940:
1925:
1919:
1918:
1916:
1914:
1903:
1897:
1896:
1894:
1892:
1886:
1880:. Archived from
1871:
1862:
1860:
1853:
1847:
1840:
1834:
1828:
1823:
1817:
1816:
1814:
1812:
1806:
1798:
1792:
1791:
1789:
1787:
1773:
1767:
1766:
1764:
1762:
1753:. Archived from
1743:
1737:
1736:
1731:
1729:
1716:
1710:
1696:
1690:
1663:
1657:
1649:
1643:
1631:
1625:
1609:
1603:
1602:
1589:
1583:
1582:
1557:
1551:
1550:
1527:
1521:
1520:
1518:
1516:2060/19930080725
1498:
1492:
1491:
1476:
1470:
1469:
1467:
1465:
1456:. Archived from
1446:
1440:
1439:
1437:
1435:
1424:
1418:
1417:
1415:
1413:
1393:
1387:
1375:
1359:
1357:
1349:
1347:
1338:
1330:
1321:
1315:
1296:
1290:
1247:
1239:
1237:
1235:
1229:
1223:. Archived from
1222:
1205:
1147:
1145:
1144:
1141:
1138:
1085:
1082:
1080:
1079:
1076:
1073:
1066:
1064:
1063:
1060:
1057:
1045:For temperature
1039:
1037:
1036:
1033:
1030:
1013:
1011:
1010:
1007:
1004:
953:
951:
950:
947:
944:
927:
925:
924:
921:
918:
887:
883:
851:
831:
828:
825:
823:
818:
815:
812:
810:
805:
802:
799:
797:
783:
780:
777:
775:
759:
751:
714:
711:
705:
702:
654:room temperature
621:31.9998 °F
618:−0.0001 °C
615:273.1499 K
584:211.971 °F
581:99.9839 °C
578:373.1339 K
546:−459.67 °F
543:−273.15 °C
512:
508:
458:, when used for
432:
427:
329:
323:
317:
222:centigrade scale
198:
193:
191:
190:
187:
184:
177:
164:
153:
147:
139:
119:
55:
43:
42:
21:
2749:
2748:
2744:
2743:
2742:
2740:
2739:
2738:
2699:
2698:
2697:
2685:
2677:
2675:
2670:
2652:
2633:Metric prefixes
2616:
2538:
2420:
2413:
2365:
2360:
2330:
2325:
2312:
2249:
2240:
2162:
2157:
2147:
2143:
2133:
2131:
2123:
2122:
2118:
2109:
2108:
2104:
2095:
2091:
2086:
2082:
2073:
2069:
2059:
2057:
2055:
2044:
2037:
2036:
2032:
2026:Wayback Machine
2012:as well as the
2001:
1997:
1986:
1982:
1972:
1970:
1953:
1952:
1948:
1938:
1936:
1926:
1922:
1912:
1910:
1905:
1904:
1900:
1890:
1888:
1887:on 10 July 2007
1884:
1869:
1858:
1856:
1854:
1850:
1841:
1837:
1826:
1824:
1820:
1810:
1808:
1804:
1800:
1799:
1795:
1785:
1783:
1775:
1774:
1770:
1760:
1758:
1757:on 5 April 2021
1745:
1744:
1740:
1727:
1725:
1718:
1717:
1713:
1697:
1693:
1688:Wayback Machine
1664:
1660:
1650:
1646:
1632:
1628:
1610:
1606:
1591:
1590:
1586:
1576:
1558:
1554:
1547:
1528:
1524:
1500:
1499:
1495:
1477:
1473:
1463:
1461:
1448:
1447:
1443:
1433:
1431:
1426:
1425:
1421:
1411:
1409:
1394:
1390:
1376:
1372:
1368:
1363:
1362:
1351:
1345:
1341:
1336:
1328:
1322:
1318:
1297:
1293:
1241:
1233:
1231:
1227:
1220:
1216:
1206:
1202:
1197:
1184:Degree of frost
1170:
1142:
1139:
1136:
1135:
1133:
1084:
1077:
1074:
1071:
1070:
1068:
1061:
1058:
1055:
1054:
1052:
1050:
1034:
1031:
1028:
1027:
1025:
1008:
1005:
1002:
1001:
999:
948:
945:
942:
941:
939:
922:
919:
916:
915:
913:
882:
869:
857:interval system
849:
838:
829:
826:
821:
820:
816:
813:
808:
807:
803:
800:
795:
794:
781:
778:
773:
772:
766:
757:
749:
723:
718:
717:
712:
708:
703:
696:
687:558.27 °R
644:−108.4 °F
604:−320.4 °F
601:−195.8 °C
594:liquid nitrogen
570:419.67 °R
492:
440:
430:
425:
392:Academy of Lyon
338:
331:
327:
325:
321:
319:
315:
212:is the unit of
194:
188:
185:
182:
181:
179:
175:
162:
154:+ 273.15)
149:
145:
137:
115:
62:
39:
28:
23:
22:
15:
12:
11:
5:
2747:
2737:
2736:
2731:
2726:
2721:
2716:
2711:
2696:
2695:
2672:
2671:
2669:
2668:
2657:
2654:
2653:
2651:
2650:
2645:
2640:
2635:
2630:
2624:
2622:
2618:
2617:
2615:
2614:
2609:
2604:
2599:
2594:
2589:
2584:
2579:
2574:
2569:
2564:
2559:
2554:
2548:
2546:
2540:
2539:
2537:
2536:
2531:
2526:
2521:
2516:
2511:
2506:
2501:
2496:
2491:
2486:
2481:
2476:
2471:
2466:
2461:
2456:
2451:
2446:
2441:
2439:degree Celsius
2436:
2431:
2425:
2423:
2419:Derived units
2415:
2414:
2412:
2411:
2406:
2401:
2396:
2391:
2386:
2381:
2375:
2373:
2367:
2366:
2359:
2358:
2351:
2344:
2336:
2327:
2326:
2317:
2314:
2313:
2311:
2310:
2305:
2300:
2295:
2290:
2285:
2280:
2275:
2270:
2265:
2260:
2254:
2251:
2250:
2239:
2238:
2231:
2224:
2216:
2210:
2209:
2201:
2193:
2185:
2175:at Wiktionary
2161:
2160:External links
2158:
2156:
2155:
2141:
2116:
2102:
2089:
2080:
2067:
2053:
2030:
1995:
1980:
1946:
1920:
1898:
1848:
1835:
1818:
1793:
1768:
1738:
1732:. p. 60:
1711:
1691:
1658:
1644:
1626:
1624:. pp. 308–310.
1604:
1584:
1574:
1552:
1545:
1522:
1493:
1471:
1441:
1419:
1388:
1369:
1367:
1364:
1361:
1360:
1316:
1291:
1289:
1288:
1285:
1277:
1199:
1198:
1196:
1193:
1192:
1191:
1186:
1181:
1176:
1169:
1166:
1091:
1090:
1042:
1041:
1015:
989:
983:
982:
972:
962:
956:
955:
929:
903:
897:
896:
893:
890:
881:
878:
868:
865:
837:
834:
830:DEGREE CELSIUS
819:, rather than
782:DEGREE CELSIUS
765:
762:
750:e.g. "30.2 °C"
739:degrees Kelvin
722:
719:
716:
715:
706:
693:
692:
689:
688:
685:
682:
679:
678:310.15 K
676:
669:
668:
665:
662:
659:
656:
649:
648:
647:351.2 °R
645:
642:
639:
636:
626:
625:
622:
619:
616:
613:
609:
608:
607:139.3 °R
605:
602:
599:
596:
589:
588:
585:
582:
579:
576:
572:
571:
568:
565:
562:
561:233.15 K
559:
551:
550:
547:
544:
541:
538:
537:Absolute zero
534:
533:
528:
523:
520:
515:
491:
488:
439:
436:
407:Daniel Ekström
353:Anders Celsius
345:Anders Celsius
337:
334:
326:
320:
314:
285:
284:degree Celsius
242:Anders Celsius
210:degree Celsius
204:
203:
173:
159:
158:
143:
134:
133:
130:
129:
124:
112:
111:
107:
106:
104:Anders Celsius
101:
97:
96:
93:
89:
88:
85:
81:
80:
75:
69:
68:
64:
63:
56:
48:
47:
46:degree Celsius
26:
9:
6:
4:
3:
2:
2746:
2735:
2732:
2730:
2727:
2725:
2722:
2720:
2717:
2715:
2712:
2710:
2707:
2706:
2704:
2694:
2689:
2684:
2683:
2680:
2667:
2659:
2658:
2655:
2649:
2646:
2644:
2641:
2639:
2636:
2634:
2631:
2629:
2626:
2625:
2623:
2619:
2613:
2610:
2608:
2605:
2603:
2600:
2598:
2595:
2593:
2590:
2588:
2585:
2583:
2580:
2578:
2575:
2573:
2572:degree of arc
2570:
2568:
2565:
2563:
2560:
2558:
2555:
2553:
2550:
2549:
2547:
2545:
2541:
2535:
2532:
2530:
2527:
2525:
2522:
2520:
2517:
2515:
2512:
2510:
2507:
2505:
2502:
2500:
2497:
2495:
2492:
2490:
2487:
2485:
2482:
2480:
2477:
2475:
2472:
2470:
2467:
2465:
2462:
2460:
2457:
2455:
2452:
2450:
2447:
2445:
2442:
2440:
2437:
2435:
2432:
2430:
2427:
2426:
2424:
2422:
2416:
2410:
2407:
2405:
2402:
2400:
2397:
2395:
2392:
2390:
2387:
2385:
2382:
2380:
2377:
2376:
2374:
2372:
2368:
2364:
2357:
2352:
2350:
2345:
2343:
2338:
2337:
2334:
2324:
2320:
2315:
2309:
2306:
2304:
2301:
2299:
2296:
2294:
2291:
2289:
2286:
2284:
2281:
2279:
2276:
2274:
2271:
2269:
2266:
2264:
2261:
2259:
2256:
2255:
2252:
2248:
2244:
2237:
2232:
2230:
2225:
2223:
2218:
2217:
2214:
2208:
2207:
2202:
2200:
2199:
2194:
2192:
2191:
2186:
2184:
2183:
2178:
2177:
2176:
2174:
2173:
2167:
2153:
2152:
2145:
2130:
2126:
2120:
2112:
2106:
2099:
2093:
2084:
2077:
2071:
2056:
2050:
2043:
2042:
2034:
2028:
2027:
2023:
2020:
2015:
2011:
2007:
2006:
1999:
1993:
1991:
1984:
1968:
1964:
1960:
1956:
1950:
1935:
1931:
1924:
1908:
1902:
1883:
1879:
1875:
1868:
1852:
1845:
1839:
1833:
1829:
1822:
1803:
1797:
1781:
1778:
1772:
1756:
1752:
1748:
1742:
1735:
1723:
1722:
1715:
1709:
1708:
1703:
1702:
1695:
1689:
1685:
1682:
1681:
1676:
1675:
1670:
1669:
1662:
1656:
1655:
1648:
1641:
1640:
1635:
1630:
1623:
1619:
1618:
1613:
1608:
1600:
1599:
1594:
1588:
1581:
1577:
1571:
1567:
1563:
1556:
1548:
1542:
1538:
1537:
1532:
1526:
1517:
1512:
1508:
1504:
1497:
1490:
1486:
1482:
1475:
1459:
1455:
1451:
1445:
1429:
1423:
1407:
1403:
1402:thoughtco.com
1399:
1392:
1385:
1384:
1379:
1374:
1370:
1355:
1344:
1334:
1326:
1320:
1313:
1309:
1305:
1301:
1295:
1286:
1283:
1278:
1275:
1274:
1272:
1268:
1264:
1260:
1255:
1251:
1245:
1226:
1219:
1214:
1210:
1207:According to
1204:
1200:
1190:
1187:
1185:
1182:
1180:
1177:
1175:
1172:
1171:
1165:
1163:
1157:
1155:
1151:
1132:
1128:
1124:
1119:
1116:
1115:of the time.
1114:
1110:
1106:
1102:
1098:
1088:
1048:
1043:
1023:
1019:
1016:
997:
993:
990:
988:
984:
980:
976:
973:
970:
966:
963:
961:
957:
937:
933:
930:
912: ×
911:
907:
904:
902:
898:
894:
892:from Celsius
891:
889:
888:
877:
875:
864:
862:
858:
853:
850:"40 °C ± 3 K"
847:
843:
833:
791:
788:provided for
787:
770:
761:
755:
747:
742:
740:
736:
732:
728:
710:
701:
699:
694:
686:
684:98.6 °F
683:
681:37.0 °C
680:
677:
675:
671:
670:
666:
663:
660:
657:
655:
651:
650:
646:
643:
640:
638:195.1 K
637:
635:
631:
628:
627:
623:
620:
617:
614:
611:
610:
606:
603:
600:
597:
595:
591:
590:
586:
583:
580:
577:
574:
573:
569:
566:
563:
560:
557:
553:
552:
548:
545:
542:
539:
536:
535:
532:
529:
527:
524:
521:
519:
516:
514:
513:
507:
505:
496:
487:
485:
481:
476:
472:
470:
465:
461:
457:
453:
448:
445:
434:
421:
419:
415:
410:
408:
404:
403:Carl Linnaeus
399:
397:
393:
389:
385:
382:In 1743, the
380:
378:
374:
370:
366:
362:
358:
354:
346:
342:
311:
307:
305:
304:Absolute zero
302:(symbol: K).
301:
297:
293:
289:
283:
280:
278:
273:
271:
267:
263:
259:
255:
251:
247:
243:
239:
235:
231:
227:
223:
219:
215:
211:
202:
197:
174:
171:
167:
160:
157:
152:
144:
142:
141:SI base units
135:
131:
128:
125:
123:
118:
114:
113:
108:
105:
102:
98:
94:
90:
86:
82:
79:
76:
74:
70:
65:
60:
54:
49:
44:
41:
37:
33:
19:
2577:electronvolt
2438:
2257:
2205:
2197:
2189:
2181:
2171:
2163:
2150:
2144:
2132:. Retrieved
2119:
2105:
2097:
2092:
2083:
2070:
2058:. Retrieved
2040:
2033:
2017:
2003:
1998:
1989:
1983:
1971:. Retrieved
1967:the original
1958:
1949:
1937:. Retrieved
1933:
1923:
1911:. Retrieved
1901:
1889:. Retrieved
1882:the original
1877:
1873:
1851:
1843:
1838:
1821:
1809:. Retrieved
1796:
1784:. Retrieved
1779:
1771:
1759:. Retrieved
1755:the original
1741:
1733:
1726:. Retrieved
1720:
1714:
1706:
1700:
1694:
1679:
1673:
1667:
1661:
1653:
1647:
1638:
1633:
1629:
1616:
1611:
1607:
1596:
1587:
1579:
1565:
1555:
1535:
1525:
1496:
1484:
1474:
1462:. Retrieved
1458:the original
1444:
1432:. Retrieved
1422:
1410:. Retrieved
1401:
1391:
1381:
1373:
1319:
1294:
1281:
1270:
1266:
1262:
1258:
1253:
1249:
1232:. Retrieved
1225:the original
1208:
1203:
1158:
1149:
1130:
1120:
1117:
1094:
1046:
1021:
1017:
995:
991:
978:
974:
968:
964:
935:
931:
909:
905:
870:
861:ratio system
854:
845:
839:
767:
743:
738:
731:SI base unit
724:
709:
667:528 °R
641:−78 °C
598:77.4 K
567:−40 °F
564:−40 °C
501:
477:
473:
463:
451:
449:
441:
423:
413:
411:
400:
381:
356:
350:
296:SI base unit
288:triple point
281:
274:
253:
249:
245:
237:
234:Kelvin scale
228:used in the
221:
217:
209:
207:
195:
150:
126:
121:
116:
84:Unit of
40:
2247:temperature
1990:SI Brochure
1973:16 November
1891:11 February
1811:16 February
1786:20 November
1531:Rittner, D.
1352:(1.39
1250:Temperature
1248:as well as
1213:Terry Quinn
1067: °F =
895:to Celsius
874:SI-prefixed
804:DEGREE SIGN
664:68 °F
661:20 °C
658:293 K
630:Sublimation
484:BBC Weather
462:. The term
444:thermometry
214:temperature
199:+ 32)
100:Named after
87:temperature
73:Unit system
59:thermometer
2703:Categories
2371:Base units
2323:comparison
2268:Fahrenheit
2134:6 February
1366:References
1282:centigrade
1267:centesimal
1263:centigrade
1242:(146
901:Fahrenheit
859:but not a
556:Fahrenheit
549:0 °R
526:Fahrenheit
452:centigrade
429:15 degrees
386:physicist
266:Fahrenheit
246:centigrade
18:Centigrade
2514:steradian
2429:becquerel
1939:22 August
1622:Neuchâtel
1434:19 August
1323:In 1948,
1113:metrology
1047:intervals
1040: °C
1014: °R
954: °C
846:intervals
632:point of
540:0 K
120: °C
2666:Category
2621:See also
2394:kilogram
2363:SI units
2308:Wedgwood
2273:Gas mark
2060:20 April
2038:"22.2".
2022:Archived
1684:Archived
1639:DE LYON.
1636:(1743):
1614:(1743):
1412:25 April
1406:Archived
1327:stated,
1168:See also
1150:strictly
1083: °R
827:℃
779:℃
672:Average
384:Lyonnais
367:'s 10th
166:Imperial
2582:hectare
2567:decibel
2509:sievert
2504:siemens
2434:coulomb
2384:candela
2298:Réaumur
2293:Rankine
2263:Delisle
2258:Celsius
2172:Celsius
2008:by the
1913:21 July
1832:YouTube
1728:10 June
1489:Fig. 1.
1380:at the
1302:at one
1271:Celsius
1259:Celsius
1254:Celsius
1146:
1134:
1131:exactly
1081:
1069:
1065:
1053:
1038:
1026:
1012:
1000:
987:Rankine
952:
940:
926:
914:
842:Gallium
769:Unicode
727:SI unit
652:Common
634:dry ice
558:scales
531:Rankine
522:Celsius
478:Due to
456:gradian
336:History
270:Liberia
262:gradian
216:on the
192:
180:
2693:Energy
2679:Portal
2597:minute
2557:dalton
2499:radian
2494:pascal
2484:newton
2409:second
2389:kelvin
2379:ampere
2288:Newton
2283:Leiden
2278:Kelvin
2243:Scales
2203:BIPM,
2179:NIST,
2051:
1987:BIPM,
1572:
1543:
1350:
1312:ITS-90
1240:
1234:31 May
1154:ITS-90
1143:273.15
1137:373.15
960:Kelvin
824:
822:U+2103
814:C
811:
809:U+0043
801:°
798:
796:U+00B0
776:
774:U+2103
735:kelvin
518:Kelvin
431:
426:
363:. The
328:
322:
316:
294:, the
292:kelvin
254:gradus
250:centum
122:in ...
92:Symbol
2612:tonne
2607:neper
2592:litre
2534:weber
2519:tesla
2474:lumen
2469:katal
2464:joule
2459:hertz
2454:henry
2444:farad
2399:metre
2303:Rømer
2045:(PDF)
1885:(PDF)
1870:(PDF)
1857:0.000
1805:(PDF)
1761:9 May
1617:LION.
1464:9 May
1346:(PDF)
1228:(PDF)
1221:(PDF)
1195:Notes
1101:VSMOW
373:dynes
172:units
2587:hour
2529:watt
2524:volt
2449:gray
2404:mole
2321:and
2136:2024
2062:2017
2049:ISBN
2014:BIPM
2010:NIST
1975:2011
1941:2007
1915:2022
1893:2007
1878:1411
1861:(10)
1813:2022
1788:2011
1763:2008
1730:2021
1570:ISBN
1541:ISBN
1466:2008
1436:2023
1414:2020
1298:For
1265:and
1236:2016
1123:CGPM
365:BIPM
208:The
34:and
2562:day
2489:ohm
2479:lux
2245:of
1859:089
1830:on
1511:hdl
1503:doi
1354:MiB
1244:KiB
433:...
424:...
379:).
377:kPa
298:of
277:atm
272:).
2705::
2127:.
1961:.
1957:.
1932:.
1876:.
1872:.
1749:.
1595:.
1578:.
1564:.
1509:.
1452:.
1404:.
1400:.
806:+
697:^
420::
238:°C
201:°F
170:US
95:°C
78:SI
57:A
2681::
2355:e
2348:t
2341:v
2235:e
2228:t
2221:v
2138:.
2113:.
2078:.
2064:.
1977:.
1943:.
1917:.
1895:.
1815:.
1790:.
1765:.
1549:.
1519:.
1513::
1505::
1468:.
1438:.
1416:.
1358:.
1356:)
1348:.
1246:)
1238:.
1140:/
1078:5
1075:/
1072:9
1062:5
1059:/
1056:9
1035:9
1032:/
1029:5
1022:x
1018:x
1009:5
1006:/
1003:9
996:x
992:x
979:x
975:x
969:x
965:x
949:9
946:/
943:5
936:x
932:x
923:5
920:/
917:9
910:x
906:x
758:′
196:x
189:5
186:/
183:9
178:(
168:/
156:K
151:x
148:(
117:x
38:.
20:)
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