50 years of Celsius weather forecasts – time to kill off Fahrenheit for good?

Fifty years ago, on 15th October 1962, British weather forecasts switched over from the Fahrenheit scale to Celsius. Fifty years on, some parts of the British media inexplicably cling on to Fahrenheit measures, and the UK Metric Association (UKMA) says it’s time to kill off Fahrenheit for good.

[Press release issued on 15 October 2012]

The UK Met Office has used the Celsius scale – formerly known as “centigrade” – in its work since 1st January 1961, to allow for greater international co-operation and because of the convenience of the scale. As the Met Office reported in 1962, this “led to the consideration of the desirability of introducing it in weather reports and forecasts for the general public.”

With the agreement of industry and the government, the Celsius scale was given after Fahrenheit from January 1962 as an interim measure, and then from the 15th October, Celsius became the primary unit given, with Fahrenheit retained as a secondary unit to aid the transition “for a period of several years.”

The Met Office is to be commended for accomplishing the change to the metric system of measurement so rapidly, in sharp contrast to some other parts of the government, such as the Department for Transport, which is still, fifty years later, dithering even about adding metres to safety-critical warning signs.

However, despite this early and rapid switch to Celsius-first forecasting, at the time of switchover, there was no timetable for the withdrawal of the Fahrenheit secondary measure. Says UKMA Chairman Robin Paice, “The officials at the Met Office in 1962 would almost certainly be incredulous at the prospect that, fifty years later, some media outlets would still be using Fahrenheit, and in some quarters, even as the primary scale. Two generations have now passed since Celsius was introduced, and yet we still see occasional headlines, normally in hot weather, about the temperature given in Fahrenheit.”

UKMA believes that with fifty years of Celsius weather forecasting now behind us, it is time for the British media to ditch Fahrenheit for good. “Media outlets should reflect on how they reported decimalisation; “new pence” are almost a decade younger than the Celsius temperature scale, and yet no newspapers feel the need to convert pence to shillings in their reports, and rightly so; why cling on to an even more obsolete temperature scale?”

The Met Office declined an invitation to comment.

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176 Responses to 50 years of Celsius weather forecasts – time to kill off Fahrenheit for good?

  1. BrianAC says:


    "Trust me I am a doctor" comes to mind. Very fitting these days.
    It seems more and more that we (the plebs of the land) are being held back in the past by the so called 'educated classes' of wisdom, no irony nor sarcasm intended.
    I am never clear as to whether this is a deliberate act of surf suppression, one of pure arrogance or just downright stupidity.

  2. Ezra Steinberg says:

    Amazing and rather confounding that a country like Canada, which is much smaller than the USA both in terms of population and the size of its economy, was able all the way back in the 1970's to convert completely to degrees Celsius. All the thermometers, radio and TV broadcasts, newspaper articles, online web sites catering to Canadians, etc. use Celsius exclusively (and they never say "Centigrade" either!).

    On top of that all the Canadians I have heard on the radio or talked to in person confess that they have no understanding of degrees Fahrenheit (even those who have lived for several years in the USA).

    I still find it very striking how Canadian media are 100% metric. Just today I watched a very recent Canadian Broadcasting program called "The National" that discussed the perils of climate change in the Far North as it affects permafrost. All of the units used were degrees Celsius (to the point where they don't even bother saying "Celsius" any more, thank you very much), along with meters, kilometers, etc.

    Of course we don't do anything close to that here in the States (alas). I understand that. What is so disappointing is how much further behind a country like the UK is compared to Canada, which is in a much more difficult position sitting right on top of the USA but much weaker than the USA whereas the UK sits in close proximity to (and even has a land border with) countries that are 100% metric!

  3. Daniel Jackson says:


    Canada switched to using degrees Celsius as one of the first changes in 1974. They did so early on thinking the US would follow suit. By the early '80s when they finally realised the US was not going to change things started to peter out, but by then they had effectively changed weather, road signs, gasoline sales, market scales, etc, and there was no desire to spend money to revert. They continued to use what had changed but changed no more. They may teach Fahrenheit in the schools, I don't know, but because they don't use it they don't remember it. The only time the issue comes up is when Americans get angry when others don't speak to them in USC.

  4. Wayne Sharp says:

    Hello, I was born in October 1963, my senior school years were 1975-1980, however I was always taught Fahrenheit not celcius, I am wondering why this was.

  5. Philip says:

    There was no degree symbol …
    Sadly it's common now just to see 'C'. I noticed this on BBC TV yesterday - the capital letter C was nice and big, but it was missing the degree symbol.

  6. Daniel Jackson says:


    You didn't tell us what country you live in. If it is the US, well the US still uses Fahrenheit and Americans are often upset when encountering people from metric countries who communicate temperatures in degrees Celsius.

    If you are from outside the US then the failure of your school to teach you Celsius either forced you to learn it on your own some time later or you spend a lot of time converting. Those who insist on using Fahrenheit in the 210st century will always be looked down upon as being Luddites.

  7. Ezra Steinberg says:

    Sadly, it looks like the USA is the only country left on the planet to use routinely and by default degrees Fahrenheit for temperature.

  8. Ezra Steinberg says:

    Despite my previous post about the lonely status of the USA and Fahrenheit, the BBC reporting on the heatwave in the UK offers up an unholy melange of Celsius and Fahrenheit. Indeed, the Fahrenheit temperature is cited at least once all by itself, probably because it refers to "100 degrees" and thus has the "snap" of a 3 digit number.


    It seems that there is still no escape from the Metric Muddle in the UK even for temperature after all these years! 🙁

  9. Daniel Jackson says:


    I opened the link and every temperature started with a degree Celsius value and a Fahrenheit in parenthesis. The only time Fahrenheit was alone was when it stated: "The Met Office said the temperature reading from Cambridge was only the second time the UK had gone over 100F.". Whether the Met Office actually said that is questionable, but it wasn't an actual temperature they were giving, just a remark of the temperature exceeding 100°F, as it actually did when the temperature was recorded at 38.1°C and converted to a Fahrenheit value that just happened to be over 100°F.

    The only people who might insist on Fahrenheit are much older people. They may also be the only people reading the news. Reports in Fahrenheit only will just drive the younger generation away. Plus, if they want to know the temperature, they just use their phone app which will be in degrees Celsius only and ignore the media report.

    On another issue with the article, I realise that the Met Office has precision instruments that can precisely display a reading to tenths of a degree in Celsius. But Consumer Grade Thermometers can precisely display to whole degrees Celsius only. For the most part, giving out temperatures to the public in tenths of a degree is foolish. In addition, that precise temperature is only true at the point it was taken and if taken at another point only a few metres away, the temperature would be different. Even by as much as a whole degree in some cases. This unneeded precision is actually imprecise to anyone not at the point the temperature was taken. A whole number for the temperature based on an average taken from different locations around the city would be precise enough for the average citizen.

    It seems that the Met Office, the Media and the Public need to be better educated on temperature measurements and the precision of instruments.

  10. BrianAC says:

    Excellent posting about the ridiculous precision of these readings. It is all just media hype.
    I noticed one of the 'record high' weather stations had spread black looking gravel around the Stevenson cage area, I will bow to superior knowledge, but I suspect that would increase the reading enough to clinch the deal.
    The town of El Azizia South of Tripoli (I have been there) often had world record temperatures, but a few years ago they were all dismissed as being false due to (according to my memory) the black rocks and tarmac runways giving false high readings. I can vouch for the heat though!

  11. Ezra Steinberg says:

    A quick check of MET Eireann (Irish Meteorological Service) shows that their website is 100% metric throughout with no way I can see of changing displayed units to Imperial. This means temperatures in Celsius, wind speeds in km/h (with the correct symbols), and barometric pressure in hectopascals.

    Roaming around a bit across some Canadian sites reveals the same story ... all metric.

  12. Phil. says:

    HSBC's Fahrenheit Temperature:-
    This morning I went into my town's branch of HSBC's Bank.
    The date display on the wall also shows the room temperature.
    I complained when I saw the temperature was in degrees F.
    When I asked 'why it wasn't in degrees Celsius?' no reply.
    I didn't have time to wait and complain directly to the Branch Manager.
    So the next time you visit your bank (not online!) or see a temperature display on a wall - just check it shows C and not F.

  13. Theo Pedlar says:

    My Mum, who is 91, always converts to Fahrenheit by the approximation of multiplying by two and adding thirty. She was in her thirties when the Met office changed but was obviously past learning anything new at that age. The thing is, the Fahrenheit scale is actually more sensible for a country in the temperate zone, such as the UK. Zero deg F is the lowest temperature we are likely to encounter and 100 deg F the highest. That’s a nice range that is superior when compared to the Celsius scale where the equivalent temperatures would be -18 deg C and 38 deg C (approximately). Also, 1 deg F is the smallest unit of change that the human body can register. I’m a scientist so minus numbers have no fear for me; the same cannot be said for the less educated members of the population though. I’m not sure about the tag “metric” being applied to Celsius though; surely it’s just a continuous scale. In the metric system one uses prefixes such as milli, micro, kilo, mega etc. Correct me if I’m wrong but I’ve never heard 1000 deg C being described as 1 kiloCelsius or a change in 0.1 deg C as 100 milliCelsius.

  14. BrianAC says:

    @ Theo Pedlar

    I am not sure I am doing the right thing by replying to this at all.
    So, your 91 year old mum prefers a totally flawed mathematical solution to a non existent problem rather than seeing what has been used around the world for over 66% of her life. If at the age of 30 you considered your mum to be past learning I find it strange she can still do the maths at 91! I certainly hope I can still learn new things when I am 91.
    You recycle this myth of the F scale to be 'more sensible' in a temperate climate, if I were a scientist I would hopefully realise there is a little more use for temperature measurements than our ambient surroundings, but then Lord Kelvin comes to our rescue on that one.
    I will pass on the 1 F'ing degree bit as having no rationale.
    "I am a scientist", If you are a scientist, then God help us!
    As I understand things, the Celsius scale is a part of the SI definitions, I am not sure about it being metric as such.
    "Correct me if I am wrong", well, not so much correcting as widening the scope of multipliers, 1000's have been around for millennia I believe. But here you trap yourself, you start by implying we only need 0 (zero) to 100 F'ies, then end up with comments about m°C, k°C, which zone do you live in?

  15. Fred says:

    For 'scientists' and others who want to use the kelvin temperature scale it offers the opportunity to use prefixes. Using symbols, here are a few: yK; mK; kK; MK; TK; and YK. I support the use of degrees Celsius.

  16. Jake says:

    @Theo Pedlar

    Thank you for your post, but it is flawed in so many respects. The argument about Fahrenheit being suited to the temperate zone does not really make sense even in the UK. The temperature in the densely populated parts of the UK very rarely falls below a few minus degrees Celsius. Perhaps in the Highlands of Scotland your zero degrees Fahrenheit is reached, but so what? Having said that, the western parts of Scotland enjoy warming from the Gulf Stream and do not suffer such extremes. Taking the other part of your argument about 100 degrees Fahrenheit being the hottest summer day in the UK, yes, with climate change some very high temperatures were experienced last year and we may see the same again this year. However - and this is a big however - as much as you may wish to 'celebrate' the three-digit Fahrenheit temperature, there are many much more important health and safety risks associated with extremely hot weather that should concern us more than having reached what might be considered a maximum Fahrenheit temperature. With a 91 year old mum, you must be - and I'm sure are you are - worried about her on those hot summer days. Those high temperatures are a cause for concern, not for celebration or because it is the 'top end' of the Fahrenheit scale as experienced in the UK. As you are a scientist, you will know that there is no 'top end' to either the Fahrenheit scale or the Celsius scale anyway. To consider that a person of any age, especially one in their thirties, is incapable of learning anything new is, in my view, a rather disrespectful thing to say. Have you tried explaining the Celsius scale to your mother? If I had spent decades watching a relative struggling with converting a temperature (or decimal currency, how does she fare with that?), I think I might have taken the time to sit down and go through the basics of the new scale the person was having difficulty with. It's never too late to learn something new!

  17. Ezra Steinberg says:

    @Theo Peldar

    Canada converted to Celsius from Fahrenheit in the 1970's. There have been no complaints in that country about that conversion since then (despite sitting right on top of and in close proximity to a huge neighbor, the USA, that still uses Fahrenheit).

  18. Daniel Jackson says:

    This claim by Theo is a typical rant of the anti-metric brigade and has no basis in fact. Yes, as others noted a person going through 60 years of converting rather than learning seems almost ridiculous. Whereas some people may do this for spite the majority will quickly adapt to the new unit. It just takes a minor effort.

    The Celsius unit works perfectly in all countries on the earth as a normal and common unit, due to the fact that temperatures anywhere on the earth fall within the -50°C to +50°C range, with 0°C being the midpoint and the boundary between freezing and non-freezing. Even in countries that never experience freezing temperatures, this system works best as temperatures can nominally fall into a suitable range such as +20°C to +40°C in tropical areas. Any range of numbers can be picked to give a suitable logical range.

    The 1° resolution of Fahrenheit thermometers is another fiction claimed without a basis in fact. First of all, analog and digital thermometers for commercial grade use can only accurately resolve to 1°C or 2°F. This is quite apparent on any analog Fahrenheit thermometer that only displays marking in 2 degree increments. Digital Fahrenheit thermometers may resolve numbers in increments of 1° but are only precise to 2°.

    High precision laboratory thermometers that cost in the thousands of euros, dollars, pounds, etc do have precision down to the 0.1°C level. Anything less than a 1°C resolution on any commercial grade thermometer is fake.

    In addition temperature is not homogeneous throughout space and can easily vary a few degrees to where a 1°F resolution gives a false result. In a room as outdoors for example, there are hot and cold spots as well as warmer areas more affected by the sun , such as near windows and doors in the summer and out in the open, as opposed to the centre of a room or in the shade of a tree or a building. Official temperatures taken at air ports may be warmer or cooler than other parts of the city. The 1°C increment gives a better average and more true reading that a 1°F increment.

    Those ignorant of science will easily be swayed by the false claims of Fahrenheit. But, it is good to know that only those in countries that are slacking in scientific development are the only ones swayed, while the rest of the world moving forward easily knows the Celsius scale is the best suited for all applications.

  19. John Smith says:

    @daniel - sorry for being that guy, but as a whole, the temperature regimes can depart quite markedly from the numbers you put forth - the coldest know temperature on Earth (verified ground monitoring station) is ?89.2 °C at the Soviet Vostok Station in Antarctica on 21 July 1983.

    Via satellite, observations showed a surface temperature of ?93.2 °C at 81.8°S 59.3°E, along a ridge between Dome Argus and Dome Fuji, at 3,900 m elevation

    With reference to a human occupied continent, on 06/02/1933 a temperature of ?67.7 °C was recorded at Oymyakon, Russia. This is the coldest officially recorded temperature in the Northern Hemisphere.

    With respect to the other extreme, if one ignores the 1913 Death Valley, CA, USA record (as there are notable issues with it) then the highest recorded air temperature on Earth is 54.0 °C, recorded both in Death Valley on June 20, 2013, and in Mitribah, Kuwait on July 21, 2016.

  20. Daniel Jackson says:

    @John Smith,

    The fact that from time to time one will encounter temperatures outside of the -50° to 50°C range doesn't detract from the fact that the temperatures in normally inhabited regions of the earth fall within the -50°C to +50°C range. As I mentioned, there may even be regions that never or rarely experience temperatures outside the 20-40°C range. Some regions may never experience a temperature above 0°C.

    Any range of temperatures can be manufactured that proves or points to a particular scale being better suited or not. The -50°C to +50°C range of the Celsius scale is much better suited for a temperature range than the claimed 0 to 100 in Fahrenheit.

    As noted also, Fahrenheit fails on a number of other claims.

  21. Martin Vlietstra says:

    From a philosophical point of view, there is little to choose between degrees Celsius and degrees Fahrenheit. Unlike most units of measure, neither scale has sub or super-multiples while, unlike kelvins or degrees Rankine, the zero point of neither scale maps onto something that is really zero (zero kelvins and zero degrees Rankine both map onto absolute zero, a point at which molecules have zero kinetic energy). Neither scale is directly related to the base units used in either SI or the foot-pound-second system. The accuracy of both scales is dependent on the transducer used rather than the scale itself.

    So which is the best? With so little to choose between the two, the pragmatic answer is to choose the one which has the most widespread use around the globe – ie degrees Celsius.

    Using such a philosophy is not new – in 1884 a conference attended by delegates from the "civilised nations of the world" [1884 terminology, not 21st century terminology] was held in Washington DC to debate the location of the prime meridian. There were two main contenders – the United Kingdom's choice of the meridian that passed through the observatory at Greenwich and the French choice of the meridian that passed through the French National Observatory. Eventually the congress came down in favour of Greenwich on grounds that British maps were more widely used than French maps.

  22. Ray says:

    Will Great Britain now change to Fahenheit as with most western countries?
    With Fahenheit its easy to understand temperture which is what we have used for hundresds of years. I am in favour of Only parts of the metric system, however we still use pints,gallons yards,feet and inches and of course Fahenheit. Centigrade has always been with us,mainly used in laboratories,not for general use.
    We are fed up of groups forcing Centigrade or Celcius, when these numbers mean nothing about temperature as we know it.

  23. Wilkins says:

    Ray, the only one of 50 or so western countries that uses Fahrenheit (not Fahenheit) is the USA. 1 in 50! Scarcely a majority. Even Canada uses Celsius (not Celcius).
    And the broadcasters have been using Celsius, initially known as centigrade, for almost 60 years. So if you wish to become familiar with the measurement unit for temperature, now used by almost 200 countries around the world, then you may wish to consider watching a few weather forecasts on TV.

  24. BrianAC says:


    Sometimes a reply to a troll is just not worth the effort!!!

  25. Daniel Jackson says:

    In response to Ray, how is it in the 50 years since the UK switched to Celsius you failed to learn it? So, everyone who did learn it and moved forward should be handicapped because you were too stubborn to make an effort to learn. The majority of people are happy with Celsius and want Celsius to stay. If you don't, that's your problem.

  26. Roger Mortimer says:

    "the pragmatic answer is to choose the one which has the most widespread use around the globe – ie degrees Celsius"

    In other words, because the cultural imperialists have been so successful already, we should hand them another victory. Would you argue that Africans should give up their own languages entirely, and instead use the supposedly "superior" ones Europeans brought them?

    There's an obvious argument for standardising *some* weights and measures to make trade simpler, but there's no reason at all different countries need use the same system during the weather forecast after the evening news.


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