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The Fahrenheit scale ( or ) is a
temperature scale Scale of temperature is a methodology of calibrating the physical quantity temperature in metrology. Empirical scales measure temperature in relation to convenient and stable parameters, such as the freezing and boiling point of water. Absolute tem ...
based on one proposed in 1724 by the
physicist A physicist is a scientist A scientist is a person who conducts scientific research The scientific method is an Empirical evidence, empirical method of acquiring knowledge that has characterized the development of science since at leas ...

physicist
Daniel Gabriel Fahrenheit Daniel (Hebrew: דָּנִיֵּאל‎ Daniyyel) , (Arabic: دانيال ''Daniyal'') is a masculine given name and a surname of Hebrew Hebrew (, , or ) is a Northwest Semitic languages, Northwest Semitic language of the Afroasiatic ...
(1686–1736). It uses the degree Fahrenheit (symbol: °F) as the unit. Several accounts of how he originally defined his scale exist, but the original paper suggests the lower defining point, 0 °F, was established as the freezing
temperature Temperature ( ) is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy Thermal radiation in visible light can be seen on this hot metalwork. Thermal energy refers to several distinct physical concept ...

temperature
of a solution of
brine Brine is a high-concentration solution of salt (NaCl) in water (H2O). In different contexts, ''brine'' may refer to salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of solutions used for brining food ...

brine
made from a mixture of water,
ice Ice is water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it acts as a ). It is vital for all known forms of , eve ...

ice
, and
ammonium chloride Ammonium chloride is an inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. However, the distinction is not clearly defi ...

ammonium chloride
(a
salt Salt is a mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure fo ...
). The other limit established was his best estimate of the average
human body temperature Normal human body-temperature (normothermia, euthermia) is the typical temperature Temperature is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy, present in all matter, which is the source of th ...
, originally set at 90 °F, then 96 °F (about 2.6 °F less than the modern value due to a later redefinition of the scaleFahrenheit temperature scale
Encyclopædia Britannica Online. 25 September 2015
). However, he noted a middle point of 32 °F, to be set to the temperature of ice water. For much of the 20th century, the Fahrenheit scale was defined by two fixed points with a 180 °F separation: the temperature at which pure water freezes was defined as 32 °F and the boiling point of water was defined to be 212 °F, both at
sea level Mean sea level (MSL) (often shortened to sea level) is an average In colloquial, ordinary language, an average is a single number taken as representative of a list of numbers, usually the sum of the numbers divided by how many numbers are in th ...

sea level
and under
standard atmospheric pressure The standard atmosphere (symbol: atm) is a unit Unit may refer to: Arts and entertainment * UNIT Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit ...
. It is now formally defined using the
Kelvin The kelvin is the base unit of temperature Temperature ( ) is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy Thermal radiation in visible light can be seen on this hot metalwork. Thermal en ...

Kelvin
scale and hence ultimately by the
Boltzmann constant The Boltzmann constant ( or ) is the proportionality factor In mathematics, two varying quantities are said to be in a Binary relation, relation of proportionality, Multiplication, multiplicatively connected to a Constant (mathematics), c ...
, the
Planck constant The Planck constant, or Planck's constant, is a fundamental physical constant A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that is generally believed to be both universal in nature an ...
, and the unperturbed
ground state The ground state of a quantum-mechanical system is its lowest-energy In , energy is the that must be to a or to perform on the body, or to it. Energy is a ; the law of states that energy can be in form, but not created or destro ...
hyperfine transition
frequency Frequency is the number of occurrences of a repeating event per unit of time A unit of time is any particular time Time is the indefinite continued sequence, progress of existence and event (philosophy), events that occur in an apparen ...

frequency
of the
caesium Caesium (IUPAC spelling) (American and British English spelling differences, also spelled cesium in American English) is a chemical element with the Symbol (chemistry), symbol Cs and atomic number 55. It is a soft, silvery-golden alkali ...

caesium
133 atom. In the first decades of the 18th century in the
Dutch Republic The United Provinces of the Netherlands, or United Provinces (officially the Republic of the Seven United Netherlands), commonly referred to in historiography Historiography is the study of the methods of historian ( 484– 425 BC) was ...
, FahrenheitDaniel Gabriel Fahrenheit was born in (Gdańsk), then a predominantly German-speaking city in the
Pomeranian Voivodeship Pomeranian Voivodeship, Pomorskie Region, or Pomerania Province (Polish Polish may refer to: * Anything from or related to Poland Poland ( pl, Polska ), officially the Republic of Poland ( pl, Rzeczpospolita Polska, links=no ), is a c ...
of the
Polish–Lithuanian Commonwealth The Polish–Lithuanian Commonwealth, formally known as the Kingdom of Poland and the Grand Duchy of Lithuania, and, after 1791, the Commonwealth of Poland, was a country and bi-federation A federation (also known as a federal state) is ...
. He later moved to the
Dutch Republic The United Provinces of the Netherlands, or United Provinces (officially the Republic of the Seven United Netherlands), commonly referred to in historiography Historiography is the study of the methods of historian ( 484– 425 BC) was ...
at age 15, where he spent the rest of his life (1701–1736).
made two revolutionary breakthroughs in the history of
thermometry , the originator of the era of precision thermometry. He invented the mercury thermometer (first practical, accurate thermometer (mercury-in-glass thermometer) for measurement of room temperature. A thermometer is a device that temperature mea ...
. He invented the
mercury-in-glass thermometer -born Daniel Gabriel Fahrenheit, a pioneer of exact thermometry (or precision thermometry). He invented the mercury thermometer (first practical, accurate thermometer) and Fahrenheit scale (first standardized temperature scale to be widely used). T ...
(first widely used, accurate, practical thermometer) Bolton, Henry Carrington: ''Evolution of the Thermometer, 1592–1743''. (
Easton, PA Easton is a city in and the county seat A county seat is an administrative centerAn administrative centre is a seat of regional administration or local government Local government is a generic term for the lowest tiers of public administrati ...

Easton, PA
: Chemical Publishing Company, 1900). Henry Carrington Bolton (1900): " ..The origin of a prime invention is sometimes obscured by the failure of the discoverer to claim definitely the product of his inspiration owing to the fact that he himself failed to appreciate its high importance and its utility. The task of sketching the origin of the thermometer is fraught with similar difficulties; the actual inventor is known only at second hand, its development from a crude toy to an instrument of precision occupied more than a century, and its early history is encumbered with erroneous statements that have been reiterated with such dogmatism that they have received the false stamp of authority."
and the Fahrenheit scale. Fahrenheit was the first standardized temperature scale to be widely used, although its use is now limited. It is the official temperature scale in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

United States
(including its unincorporated territories), its freely associated states in the Western Pacific (
Palau Palau (), officially the Republic of Palau ( pau, Beluu er a Belau) and historically ''Belau'', ''Palaos'' or ''Pelew'', is an island country An island country or an island nation is a country A country is a distinct territory, t ...

Palau
, the
Federated States of Micronesia The Federated States of Micronesia (; abbreviated FSM), or simply Micronesia, is an island country An island country or an island nation is a country A country is a distinct territory, territorial body or political entity. It is oft ...
and the
Marshall Islands The Marshall Islands, officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ), is an independent near the in the , slightly west of the . Geographically, the country is part of the larger island group of . The countr ...
), the
Cayman Islands The Cayman Islands () is a self-governing British overseas territories, British Overseas Territory, the largest by population, in the western Caribbean Sea. The territory comprises the three islands of Grand Cayman, Cayman Brac and Little Caym ...

Cayman Islands
, and the former American colony of
Liberia Liberia (), officially the Republic of Liberia, is a country on the West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 17 countries of Benin, Burkina Faso, Cape ...

Liberia
. Fahrenheit is used alongside the
Celsius The degree Celsius is a unit of temperature on the Celsius scale, a temperature scale Scale of temperature is a methodology of calibrating the physical quantity temperature in metrology. Empirical scales measure temperature in relation to conv ...

Celsius
scale in
Antigua and Barbuda Antigua and Barbuda (; ) is a sovereign state, sovereign island country in the West Indies in the Americas, lying between the Caribbean Sea and the Atlantic Ocean. It consists of two major islands, Antigua and Barbuda separated by , and smal ...
and other countries which use the same
meteorological Meteorology is a branch of the atmospheric sciences which includes atmospheric chemistry and atmospheric physics, with a major focus on weather forecasting Weather forecasting is the application of science and technology to predict the ...
service, such as
Saint Kitts and Nevis Saint Kitts and Nevis (), officially the Federation of Saint Christopher and Nevis, is an island country in the West Indies. Located in the Leeward Islands chain of the Lesser Antilles, it is the smallest sovereign state in the Western Hemis ...
, the
Bahamas The Bahamas (), known officially as The Commonwealth of The Bahamas, is a sovereign country within the Lucayan Archipelago of the West Indies in the Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the a ...
, and Belize. A handful of
British Overseas Territories The British Overseas Territories (BOTs), also known as United Kingdom Overseas Territories (UKOTs), are fourteen dependent territory, territories all with a constitutional and historical link with the United Kingdom. They are remnants of the B ...

British Overseas Territories
still use both scales, including the
British Virgin Islands ) , anthem = "God Save the Queen "God Save the Queen", alternatively "God Save the King" (dependent on the gender of the reigning monarch), is the or in most s, their territories, and the British . The author of the tune is unknown, an ...

British Virgin Islands
,
Montserrat Montserrat ( ) is a British Overseas Territory The British Overseas Territories (BOTs), also known as United Kingdom Overseas Territories (UKOTs), are fourteen dependent territory, territories all with a constitutional and historical lin ...

Montserrat
,
Anguilla Anguilla ( ) is a British overseas territory The British Overseas Territories (BOTs), also known as United Kingdom Overseas Territories (UKOTs), are fourteen territories all with a constitutional and historical link with the United Kin ...

Anguilla
, and Bermuda. In the United Kingdom, degrees Fahrenheit figures are sometimes used in newspaper headlines to sensationalize heatwaves. All other countries now use
Celsius The degree Celsius is a unit of temperature on the Celsius scale, a temperature scale Scale of temperature is a methodology of calibrating the physical quantity temperature in metrology. Empirical scales measure temperature in relation to conv ...

Celsius
(also known as ''centigrade''), a scale formalized about 20 years after the Fahrenheit scale. However, the name ''Celsius'' was given to the centigrade scale much later, in 1948, in honor of Swedish
astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

astronomer
Anders Celsius Anders Celsius (, 27 November 170125 April 1744) was a Swedish astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical o ...

Anders Celsius
.


Definition and conversion

Historically, on the Fahrenheit scale the
melting point The melting point (or, rarely, liquefaction point) of a substance is the temperature Temperature ( ) is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy Thermal radiation in visible light can b ...

melting point
of water was 32°F and the
boiling point The boiling point of a substance is the temperature at which the vapor pressure 280px, The ''pistol test tube'' experiment. The tube contains alcohol and is closed with a piece of cork. By heating the alcohol, the vapors fill in the space, inc ...
was 212°F (at
standard atmospheric pressure The standard atmosphere (symbol: atm) is a unit Unit may refer to: Arts and entertainment * UNIT Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit ...
). This put the boiling and freezing points of water 180 degrees apart. Therefore, a degree on the Fahrenheit scale was of the interval between the freezing point and the boiling point. On the Celsius scale, the freezing and boiling points of water were originally defined to be 100 degrees apart. A temperature interval of 1 °F was equal to an interval of  degrees Celsius. With the Fahrenheit and Celsius scales now both defined by the kelvin this relationship was preserved, a temperature interval of 1 °F being equal to an interval of  kelvins and of  degrees Celsius. The Fahrenheit and Celsius scales intersect at −40° (i.e. −40 °F = −40 °C).
Absolute zero Absolute zero is the lowest limit of the thermodynamic temperature Thermodynamic temperature is the measure of ''absolute temperature'' and is one of the principal parameters of thermodynamics. A thermodynamic temperature reading of zero deno ...
is 0 K, −273.15 °C, or −459.67 °F. The Rankine temperature scale uses degree intervals of the same size as those of the Fahrenheit scale, except that absolute zero is 0 °R — the same way that the
Kelvin The kelvin is the base unit of temperature Temperature ( ) is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy Thermal radiation in visible light can be seen on this hot metalwork. Thermal en ...

Kelvin
temperature scale matches the Celsius scale, except that absolute zero is 0 K. The combination of
degree symbol The degree symbol or degree sign, , is a typographical symbol This is a list of the most common typographical symbols and punctuation marks used in western European languages. For a far more comprehensive list of symbols and signs, see List of U ...

degree symbol
(°) followed by an uppercase letter F is the conventional symbol for the Fahrenheit temperature scale. A number followed by this symbol (and separated from it with a space) denotes a specific temperature point (e.g. "
Gallium Gallium is a chemical element with the Symbol (chemistry), symbol Ga and atomic number 31. Discovered by France, French chemist Paul-Émile Lecoq de Boisbaudran in 1875, Gallium is in boron group, group 13 of the periodic table and is ...

Gallium
melts at 85.5763 °F"), a difference between temperatures (e.g. "The output of the heat exchanger experiences an increase of 72 °F") or an uncertainty in temperature (e.g. "Our standard uncertainty is ±5 °F").Grigull, Ulrich (1966). ''Fahrenheit, a Pioneer of Exact Thermometry''. (The Proceedings of the 8th International Heat Transfer Conference, San Francisco, 1966, Vol. 1, pp. 9–18.) The symbol for the Celsius scale also uses the degree symbol (°C), while the symbol for the Kelvin scale is just an uppercase letter K. The numerical value of a temperature difference or temperature interval is the same when expressed in either degrees Celsius or in kelvin.


Conversion (specific temperature point)

For an exact conversion between Fahrenheit, Celsius, and kelvins of ''a specific temperature point'', the following formulas can be applied. Here, is the value in Fahrenheit, the value in Celsius, and the value in kelvins: *  °Fahrenheit to  °Celsius: = *  °Celsius to  °Fahrenheit: = × 1.8 + 32 *  °Fahrenheit to  kelvins: = *  kelvins to  °Fahrenheit: = × 1.8 - 459.67 There is also an exact conversion between Celsius and Fahrenheit making use of the equality −40 °F = −40 °C. Again, is the value in Fahrenheit and the value in Celsius: *  °Fahrenheit to  °Celsius : . *  °Celsius to  °Fahrenheit : .


Conversion (temperature difference or interval)

When converting a ''temperature interval'' between °F and °C, only the ratio is used, without any constant (in this case, the interval has the same numeric value in kelvins as in degrees Celsius): * °Fahrenheit to  °Celsius or kelvins: = = * °Celsius or kelvins to  °Fahrenheit: = × 1.8 = × 1.8


History

Fahrenheit proposed his temperature scale in 1724, basing it on two reference points of temperature. In his initial scale (which is not the final Fahrenheit scale), the zero point was determined by placing the
thermometer (mercury-in-glass thermometer) for measurement of room temperature. A thermometer is a device that temperature measurement, measures temperature or a temperature gradient A temperature gradient is a physical quantity that describes in which dir ...

thermometer
in "a mixture of
ice Ice is water Water (chemical formula H2O) is an , transparent, tasteless, odorless, and , which is the main constituent of 's and the s of all known living organisms (in which it acts as a ). It is vital for all known forms of , eve ...

ice
, water, and ''salis Armoniaci'' [transl.
ammonium chloride Ammonium chloride is an inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. However, the distinction is not clearly defi ...

ammonium chloride
] or even sea salt". This combination forms a eutectic system which stabilizes its temperature automatically: 0 °F was defined to be that stable temperature. A second point, 96 degrees, was approximately the human body's temperature (''sanguine hominis sani'', the blood of a healthy person).Fahrenheit, Daniele Gabr. (1724
Experimenta & observationes de congelatione aquæ in vacuo factæ a D. G. Fahrenheit, R. S. S
(Experiments and observations on water freezing in the void by D. G. Fahrenheit, R. S. S.), ''Philosophical Transactions of the Royal Society of London'', vol. 33, no. 382, page 78 (March–April 1724). Cited and translated in http://www.sizes.com:80/units/temperature_Fahrenheit.htm
A third point, 32 degrees, was marked as being the temperature of ice and water "without the aforementioned salts". According to a German story, Fahrenheit actually chose the lowest air temperature measured in his hometown (Gdańsk,
Poland Poland, officially the Republic of Poland, is a country located in Central Europe. It is divided into 16 Voivodeships of Poland, administrative provinces, covering an area of , and has a largely Temperate climate, temperate seasonal cli ...

Poland
) in winter 1708-09 as 0 °F, and only later had the need to be able to make this value reproducible using brine. According to a letter Fahrenheit wrote to his friend
Herman Boerhaave Herman Boerhaave (, 31 December 1668 – 23 September 1738Underwood, E. Ashworth. "Boerhaave After Three Hundred Years." ''The British Medical Journal'' 4, no. 5634 (1968): 820–25. https://www.jstor.org/stable/20395297.) was a Dutch botanist ...

Herman Boerhaave
, his scale was built on the work of , whom he had met earlier. In Rømer's scale, brine freezes at zero, water freezes and melts at 7.5 degrees, body temperature is 22.5, and water boils at 60 degrees. Fahrenheit multiplied each value by four in order to eliminate fractions and make the scale more
fine-grained Granularity (also called graininess), the condition of existing in granules or Grain, grains, refers to the extent to which a material or system is composed of distinction (philosophy), distinguishable pieces. It can either refer to the extent ...
. He then re-calibrated his scale using the melting point of ice and normal human body temperature (which were at 30 and 90 degrees); he adjusted the scale so that the melting point of ice would be 32 degrees and body temperature 96 degrees, so that 64 intervals would separate the two, allowing him to mark degree lines on his instruments by simply bisecting the interval six times (since 64 is 2 to the sixth power). Fahrenheit soon after observed that water boils at about 212 degrees using this scale. The use of the freezing and boiling points of water as thermometer fixed reference points became popular following the work of
Anders Celsius Anders Celsius (, 27 November 170125 April 1744) was a Swedish astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical o ...

Anders Celsius
and these fixed points were adopted by a committee of the
Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. Founded on 28 November 1660, it was granted a royal charter by Charles II of ...
led by
Henry Cavendish Henry Cavendish FRS FRS may also refer to: Government and politics * Facility Registry System, a centrally managed Environmental Protection Agency database that identifies places of environmental interest in the United States * Family Resourc ...
in 1776. Under this system, the Fahrenheit scale is redefined slightly so that the freezing point of water was exactly 32 °F, and the boiling point was exactly 212 °F or 180 degrees higher. It is for this reason that
normal human body temperature Normal human body-temperature (normothermia, euthermia) is the typical temperature Temperature is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy, present in all matter, which is the source of th ...
is approximately 98.6° (oral temperature) on the revised scale (whereas it was 90° on Fahrenheit's multiplication of Rømer, and 96° on his original scale). In the present-day Fahrenheit scale, 0 °F no longer corresponds to the eutectic temperature of ammonium chloride brine as described above. Instead, that eutectic is at approximately 4 °F on the final Fahrenheit scale. The Rankine temperature scale was based upon the Fahrenheit temperature scale, with its zero representing
absolute zero Absolute zero is the lowest limit of the thermodynamic temperature Thermodynamic temperature is the measure of ''absolute temperature'' and is one of the principal parameters of thermodynamics. A thermodynamic temperature reading of zero deno ...
instead.


Usage

The Fahrenheit scale was the primary temperature standard for climatic, industrial and medical purposes in English-speaking countries until the 1960s. In the late 1960s and 1970s, the Celsius scale replaced Fahrenheit in almost all of those countries—with the notable exception of the United States and in certain cases, the United Kingdom—typically during their general
metrication Metrication or metrification is the act or process of converting to a metric METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is a computer model Computer simulation is the process of mathematical model ...

metrication
process. Fahrenheit is used in the United States, its territories and associated states (all served by the U.S.
National Weather Service The National Weather Service (NWS) is an agency Agency may refer to: * a governmental or other institution Institutions, according to Samuel P. Huntington, are "stable, valued, recurring patterns of behavior". Institutions can refer to m ...
), as well as the
Cayman Islands The Cayman Islands () is a self-governing British overseas territories, British Overseas Territory, the largest by population, in the western Caribbean Sea. The territory comprises the three islands of Grand Cayman, Cayman Brac and Little Caym ...

Cayman Islands
and
Liberia Liberia (), officially the Republic of Liberia, is a country on the West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 17 countries of Benin, Burkina Faso, Cape ...

Liberia
for everyday applications. For example, U.S. weather forecasts, food cooking, and freezing temperatures are typically given in degrees Fahrenheit. Scientists, including meteorologists, use degrees Celsius or kelvin in all countries. Early in the 20th century,
Halsey Halsey may refer to: People *Halsey (surname), including a list of people *Halsey (singer) (born 1994), American singer and songwriter *Halsey baronets, a title in the Baronetage of the United Kingdom Places in the United States * Halsey, Oregon, ...
and Dale suggested that reasons for resistance to use the centigrade (now Celsius) system in the U.S. included the larger size of each degree Celsius and the lower zero point in the Fahrenheit system. Canada has passed legislation favoring the
International System of Units The International System of Units, known by the international abbreviation SI in all languages and sometimes Pleonasm#Acronyms_and_initialisms, pleonastically as the SI system, is the modern form of the metric system and the world's most wi ...
, while also maintaining legal definitions for traditional Canadian imperial units. Canadian weather reports are conveyed using degrees Celsius with occasional reference to Fahrenheit especially for cross-border broadcasts. Fahrenheit is still used on virtually all Canadian ovens. Thermometers, both digital and analog, sold in Canada usually employ both the Celsius and Fahrenheit scales. In the European Union, it is mandatory to use kelvins or degrees Celsius when quoting temperature for "economic, public health, public safety and administrative" purposes, though degrees Fahrenheit may be used alongside degrees Celsius as a supplementary unit. For example, the laundry symbols used in the United Kingdom follow the recommendations of ISO 3758:2005 showing the temperature of the washing machine water in degrees Celsius only. The equivalent label in North America uses one to six dots to denote temperature with an optional temperature in degrees Celsius. While historically popular, Fahrenheit is not commonly used in the United Kingdom in daily conversation. Within unregulated sectors, such as journalism, the use of Fahrenheit in the United Kingdom follows no fixed pattern with degrees Fahrenheit sometimes appearing alongside degrees Celsius. ''
The Daily Telegraph ''The Daily Telegraph'', known online and elsewhere as ''The Telegraph'' (), is a national British daily broadsheet A broadsheet is the largest newspaper format and is characterized by long vertical pages, typically of . Other common ne ...

The Daily Telegraph
'' does not mention Fahrenheit on its daily weather page while ''
The Times ''The Times'' is a British Newspaper#Daily, daily Newspaper#National, national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its s ...
'' also has an all-metric daily weather page but has a Celsius-to-Fahrenheit conversion table. When publishing news stories, some UK tabloids have adopted a tendency of using degrees Celsius in headlines and discussion relating to low temperatures and Fahrenheit for mid to high temperatures. In February 2006, the writer of an article in ''
The Times ''The Times'' is a British Newspaper#Daily, daily Newspaper#National, national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its s ...
'' suggested that the rationale was one of emphasis: "−6 °C" sounds colder than "21 °F" and "94 °F" sounds more impressive than "34 °C".


Unicode representation of symbol

Unicode Unicode, formally the Unicode Standard, is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expressed in most of the world's wri ...

Unicode
provides the Fahrenheit symbol at code point . However, this is a compatibility character encoded for roundtrip compatibility with legacy encodings. The Unicode standard explicitly discourages the use of this character: "The sequence + is preferred over , and those two sequences should be treated as identical for searching."


See also

*
Comparison of temperature scales This is a collection of temperature conversion formulas and comparisons among eight different temperature scales, several of which have long been obsolete. Celsius Fahrenheit Kelvin Rankine Delisle Sir Isaac Newton's Degr ...

Comparison of temperature scales
*
Degree of frost A degree of frost is a non-standard unit of measurement, unit of measure for air temperature meaning degree (temperature), degrees below melting point (also known as "freezing point") of water (0 degrees Celsius or 32 degrees Fahrenheit). "Degree" i ...


Footnotes


Notes and references


External links

* *
Daniel Gabriel Fahrenheit (Polish-born Dutch physicist) – Encyclopædia Britannica

"At Auction , One of Only Three Original Fahrenheit Thermometers"
''Enfilade'' page for 2012 ''
Christie's Christie's is a British auction house An auction is usually a process of buying and selling goods In economics Economics () is the social science that studies how people interact with value; in particular, the Production (economi ...

Christie's
'' sale of a Fahrenheit mercury thermometer with some nice pictures
''Christie's'' press release
* {{United States Customary Units Customary units of measurement in the United States Imperial units Scales of temperature Science and technology in the Dutch Republic Dutch inventions 1724 introductions