Click images for more details



Recent comments
Recent posts
Currently discussing

A few sites I've stumbled across recently....

Powered by Squarespace

Discussion > What's The Difference Between Measured UHI and Met Office weather forecasts

Mark Hodgson

If you are going to have one station in an area, the airport is the logical place to put it, even if it means a relocation.

For example, relocate the Chicago city station to O'Hare.

In Ulster the Enniskillen station moved to St Angelo when the airfield was built during WW2.

Most new airports are built outside cities, sometimes because the city has grown around the old one. Think of Orly being replaced by Charles de Gaulle or the new island airport replacing Kai Tak in Hong Kong. The weather stations would have gone with them.

Any rational planner would have moved Heathrow to a new site outside the M25 by now!

Oct 20, 2016 at 9:55 PM | Unregistered CommenterEntropic man

EM 9:55 All good points, including the relocation of Heathrow, but the cost of moving the infrastructure would be excessive.

Heathrow was chosen as London's new commercial airport, because it was outside "London" at the time, but close enough. Neville Chamberlain waved a piece of paper with Herr Hitler's autograph on it, at Heston Aerodrome, not Heathrow, Hendon or Uxbridge. The reason I mention Heathrow (again) is that the BBC and Met Office keep mentioning it. As it makes Climate Science look stupid, I am happy to keep mentioning Heathrow for as long as Climate Scientists are happy to keep mentioning Heathrow Airport. It is the best evidence of UHI, but the BBC and Met Office never mention that.

The concept of weather forecasts/warnings had always been local. The telegraph made it possible to relay info quicker, but WW1 and the RFC/RAF made the formation of the Met Office as part of the then Ministry of Defence a priority in 1919.

All?/most? RAF bases had their own Met Office employees until recently with weather stations, and civilian airports had the same. Even in the internet age, the BBC Shipping Forecast on Long Wave is still valued by seafarers and their families. They don't care about the rain very much, but where the Low is, is it deepening, and which way is it moving.

Work and private stuff has taken me to many RAF bases, and Met Office sites not on RAF bases.

Where is the temperature data for RAF Benson? What about Benbecula on the Western Isles? (it has an RAF weather monitoring station) Last I heard was that Benbecula is just as bloody cold as it ever was.

Why doesn't the Met Office, BBC and Climate Science report on data that is from credible locations? The data exists. Perhaps it doesn't "sell the sizzle"?

ps I do not consider V Venema a credible source of info.

Oct 20, 2016 at 10:50 PM | Unregistered Commentergolf charlie

Entropic man,
thanks for the replies. Acouple of brief thoughts before bed.

My worry about UHI is that it is raising the average global temperature as measured on land, where most measurements are made. The Ocean Temperature and what effect it has is irrelevant to historical land data and a diversion deliberate or otherwise to the original question. As UHI is not an artifact of CO2 and is grossly under estimated due to the factors I have described then reducing CO2 emissions won't address rising temperatures. Growing urbanisation correlates well with rising temperatures which is another consideration.

Airports are of course an urban heat island too. Having lived within a few miles of East Midlands Airport for 35 years (Round The Horne anyone?) and seen it grow from a minor airfield to the major hub it is now I can't help feeling that all new airports can have had anything other than a similar or greater impact in their locations. So maybe Orly and CDG are cooler than central Paris but they will still be much warmer than rural Picardie.

Oct 20, 2016 at 11:35 PM | Unregistered CommenterSandyS

SandyS 11:35 I will leave EM to answer your questions, but further to mine at 10:50 ......

Does France have favoured places for reporting "record breaking temperatures" like Heathrow in the UK? Are they airports and hence UHIs?

I have suggested RAF Benson in Oxfordshire as an RAF Station because it is regularly reported to have had the coldest England temperature (it is a frost pocket) and Benbecula in the Western Isles because it sticks out into the sea. Are you aware of some obvious French locations off Brittany for example, or even in some distant colony, that may have meteorological records going back about 100 years?

Separately on rising sea levels, I note from internet photos of U-Boat Pens in La Rochelle, that they do not seem at risk of immediate inundation at high tide.

Oct 21, 2016 at 2:21 AM | Unregistered Commentergolf charlie

Golf Charlie
I haven't noticed any reporting of record highs and lows on BFMTV, my main news viewing on French TV, but will keep an eye out for it in future. There are reports of high temperatures in certain locations but my feeling is they are fairly random. I have noticed many reports of the effect of the weather on tourism, cold spring no-one visiting beach, canicule beaches packed, no snow no skiing, lots of snow skiers every where that kind of thing. Tourism is important bot for the Frenxh themselves who spend lots of time on beaches and skiing and for the income it brings to the country.

There are a lot of reports about pollution in Paris during anticyclonic weather, particularly in winter. Apparently a lot of wood is still used for domestic heating in Paris. I guess smog will have an effect on recorded temperatures for Paris although what they have doesn't come close to 1950's London.

Oct 21, 2016 at 8:08 AM | Unregistered CommenterSandyS


Please keep focussed on the pea. I have no issue with the logic of temperature records being kept at airports, nor regarding the occasional relocation of airports.

The issue is that airports are warmer, not cooler, being well-recognised UHIs in their own right - but Victor Venema claims the opposite. It is no coincidence that Heathrow regularly sets records claimed by the Met Office and the BBC. I cannot trust the adjustments made by people who make such basic mistakes.

Oct 21, 2016 at 8:48 AM | Unregistered CommenterMark Hodgson

Mark Hodgson, I have no issue with weather stations at military and commercial airports. The problem is that in the UK, our taxpayer funded data comes from them, and they provide a record going back a maximum of just under 100 years being RFC/RAF/MOD, which is very impressive. But ........

Very few WW2 RAF airfields had tarmac runways. There were no jets. Temperature readings relied on someone looking at a thermometer calibrated in degrees, not tenths of degrees, etc etc

Anyone who has flown to an airport where you have to walk down external steps from the aircraft to a bus, knows how the heat from the tarmac "hits you". Heathrow must also hold records for the greatest volume of airconditioned space, between entering the terminal buildings on foot, and sitting down in your aircraft seat.

Oct 21, 2016 at 11:58 AM | Unregistered Commentergolf charlie

SandyS, thank you for your response. I hadn't thought of the importance of snow, to French levels of comfort and tourism!

Did France have stories about economic doom due to the loss of Alpine snow cover, and children not knowing what snow was?

Oct 21, 2016 at 12:03 PM | Unregistered Commentergolf charlie

Mark Hodgson

I am not sure that most airfields are hotbeds(sorry) of UHI. Between my model flying, PPL and air display interests I have spent considerable time on airfields.

Heathrow is atypical. It has two parallel runways, a high density of concrete and tarmac, and is surrounded by West London. It needs a weather station to guide it's operation. It is not surprising that this station regularly generates record temperatures.

It is the exception. Most airfields have one or two tarmac runways, a few buildings in one corner and acres of unobstructed grass. They tend to be cold, windswept places. RAF Benson fits that mould and can be bloody freezing on what would otherwise be regarded as a normal day.

Golf Charlie, who also has experience of airfields, can confirm this.

Oct 21, 2016 at 12:10 PM | Unregistered CommenterEntropic man


You can see the difference between the land-based station data and the land-ocean data at the GISS website.

Scroll down to the Global Monthly Mean Surface Temperature Change graph.You will see the station data in black and the land-ocean data in red.

The station data averages 0.1C warmer than the land-ocean data. The station data is also "peakier" Warm peaks can be 0.2C warmer than the land-ocean data. This is to be expected. The greater heat capacity of the oceans tends to damp out short term temperature variations.

Otherwise the the two datasets track closely and show a similar trend.

Oct 21, 2016 at 1:14 PM | Unregistered CommenterEntropic man

Golf Charlie
I haven't seen much on not knowing what snow is, but they certainly worry about "global warming" and "climate change" in the media. Paris saw an uptick in coverage of weather extremes.

Oct 21, 2016 at 1:34 PM | Unregistered CommenterSandyS

Entropic man
One thing at a time. I'm really interested in urban/rural temperature difference as highlighted by Mer Office weather forecasts but not accounted for in calculations for UHI for global temperatures. Ocean temperatures are irrelevant to this issue. Today's forecast again has the much colder in remote areas caveat.

Are you implying that temperatures in these remote areas have tracked urban temperatures? If they haven't then there is an issue isn't there? I struggle with the idea that this tracking has happened as it means that by some means that cities and airports have been built in the warmest locations.

Oct 21, 2016 at 1:52 PM | Unregistered CommenterSandyS

EM, I have never been to Benbecula in the Western Isles off the coast of Scotland, but can confirm that RAF Benson is in a frost pocket, and is cold.

The RAF expanded rapidly in the 1920s-30s. Just as the Army expanded in the Victorian era, and got the cheaper land of little agricultural value (Aldershot, Salisbury Plain, Thetford, Catterick etc) the RAF saw any threat coming from Europe, wanting fighter bases around the south and east coast, and near potential targets. Fighters were to defend Britain, single seaters, small and light, and therefore needed much shorter runways. Bombers were bigger, and had to have bigger range in order to take the fight to any enemy. To carry the bombs, and fuel, they needed much longer runways.

The cheaper and more desirable plots were flattish plains on higher ground. (RAF Benson is one of many exceptions) RAF bases tend to be in cold windswept places, that can be beautiful in summer, but pretty bleak for the rest of the year.

Fighters could use bomber bases, but bombers could not use fighter bases with their short runways. Fighter bases were then the first to be closed after WW2.

The strategic importance of the UK Met Office is such that it retains some MOD funding. Perhaps now that it is to be divorced from the BBC, it can concentrate on weather forecasting, not dramatic publicity through scaremongering about climate.

Oct 21, 2016 at 2:15 PM | Unregistered Commentergolf charlie

SandyS 1:52, all the more reason for MOD/RAF/Met Office records from Benbecula to be published!

Oct 21, 2016 at 2:19 PM | Unregistered Commentergolf charlie

Golf Charlie

30 seconds research got me temperature averages for Benbecula for the last 30 years.

I am sure there is more available. Lett us know what you find.

Oct 21, 2016 at 7:04 PM | Unregistered CommenterEntropic man


Urban areas cover 3% of the land surface.

Since the land surface is 30% of the total, urban areas cover just under 1% of the total surface.

Because of the lower albedo UHI produces a ∆T relative to the surrounding rural area.

Quick BOE calculation. For an average UHI ∆T of 1C, then the increase in global average temperature due to UHI will be

∆T * fraction of total surface urbanised. This is 1 * 1/100=0.01C.

A world with cities is 0.01C warmer, per degree of UHI, than a world without cities. I see no reason to get excited about UHI.

If you have a different calculation available, perhaps you could share it.

Oct 21, 2016 at 7:25 PM | Unregistered CommenterEntropic man


Lies, damned lies and statistics, all over again. First of all, from the article you link to:

""We know that this is an undercount, because the poorest countries have urban areas that were either hard to detect with the satellite or have weak census-taking," said Deborah Balk of the Center for International Earth Science Information Network (CIESIN). "

Secondly, even if the 3% figure is correct, it almost certainly isn't true of the main areas where temperature datasets have run for the longest periods and are most intensively relied upon - UK, most obviously, Europe (western Europe especially) and the contiguous USA.

Saying that urban areas cover 3% of the land surface isn't remotely the same as saying that UHI is relevant to only 3% of temperature datasets.

-3 from me, for failed logic.

Oct 21, 2016 at 7:56 PM | Unregistered CommenterMark Hodgson

Burn that envelope EM

Oct 21, 2016 at 8:38 PM | Unregistered CommenterACK

Mark Hodgson

No need to be rude. I am not trying any lies,dammed lies, statistics tricks. I am trying to use basic physics to estimate the scale of the UHI effect on the global average for myself, rather than relying on outside sources. Good scepticism.

As is my habit when checking basic physics, that was a minimum calculation, ignoring all sampling considerations to get an idea of the scale of the effect. I came up with a very low figure, 0.01C per 1C UHI ∆T worldwide. This is consistent with the homogenisation correction used by the professionals.

A few other numbers.

For the UK Urban areas make up 7.9% of the total. By my formula, that would increase the UK average temperature by 0.07C per C of ∆T.

For the US urban areas make up 3.5% of the total area so the UHI effect is a ∆T of 0.035C.

For Europe urban cover is 4.6% and thechange due to 1C ofUHI degree is 0.046C.

You and SandyS seem convinced that UHI is boosting the global average much more than my figure.

What figures are you using for the effect of UHI on the global or regional average temperatures?

Oct 21, 2016 at 8:57 PM | Unregistered CommenterEntropic man


You know yourself that science is best done with numbers.Do you have any UHI numbers to put into the pool?

Oct 21, 2016 at 8:59 PM | Unregistered CommenterEntropic man

EM, the problem with "UHI Numbers and Statistics" is that they have all been adjusted and homogenised to downplay the effect of UHI, so that climate science can claim it is not the cause of global warming.

As with most things about climate science, it is peer reviewed by fellow climate scientists and hence guaranteed to be unreliable science. I am not a mathematician, but the more dependent science becomes on complicated mathematical techniques to "prove" something, the more likely it is to be wrong. It is the same as accountancy and financial fraud.

Oct 21, 2016 at 10:38 PM | Unregistered Commentergolf charlie

Golf Charlie

It is always worth going back to first principles if you can. It helps distinguish reality and bullshit. I made a completely independent UHI calculation and ended up with a result similar to the professionals. If they were fiddling the data, my calculation would not have agreed with theirs.

They don't have to be complex calculations. I get along well enough using A Level Physics and O Level algebra.

It would be worth relearning some of your school mathematics. Nothing like checking the numbers yourself to show when an argument is dubious.

Oct 21, 2016 at 11:28 PM | Unregistered CommenterEntropic man

EM, whose maths/formulae/statistics were you using?

I did believe in Mann's Hockey Stick. Now I don't. I know what a pack of lies it was. Nothing predicted/projected has happened, that hasn't happened before, many times in history.

Climate science needs to come clean about what should be saved.

We have just had the anniversary of the big storm of 15/16 October 1987. No mention on the BBC or Met Office, about that being the sort of weather we can expect more of, because it hasn't. Michael Fish presented the infamous weather forecast, but it was written by Ian McCaskgill. I have been in the same room when he has said so. On the 16th October, I was involved in sorting out storm damage at a Met Office facility, and saw their recorded data. In the summer of 1987, I had a small involvement with the installation of the new super computer at Bracknell that was going to revolutionise weather forecasting.

Having fallen for climate science lies once, why should I trust climate science now, when my work and private life has brought me into so many people with direct experience of weather, and weather forecasting? Farmers, gardeners, pilots, seafarers -sail and power, leisure, commercial, military?

As Climate Science funding is cut, taxpayers and politicians will all breathe easier. France is now ditching carbon taxes. France does not care for the Paris Climate Agreement, why should anyone else in the EU? The Climate Science Party decade is over. Last one out, turn off the lights?

Oct 22, 2016 at 12:19 AM | Unregistered Commentergolf charlie

Entropic man,
What percentage of global temperatures are taken in remote rural areas unaffected by urban reduced albedo? My original point is that the papers you quote say UHI is insignificant whilst the Met Office says that the difference is several degrees and could be more in certain places during anti-cyclonic conditions. Nothing you've said or quoted explains the difference or how it is accounted for,

The area of urbanisation isn't really relevant, it's whether or not the measurements are taken in remote rural, semi-urban or urban locations. Altnaharra and Benbecula could be considered remote rural, although as Benbecula is surround by the North Atlantic I would suggest that it is unlikely to have extremes of heat or cold compared to Altnaharra, but won't be affected by UHI from Stornaway (pop 8000).

For example The MO claims that CET is adjusted against neighbouring rural stations but just how rural are these stations are they the ones showing several degrees difference and is the prevailing weather taken into account?

Oct 22, 2016 at 1:03 AM | Unregistered CommenterSandyS


I don't believe I was being rude (though if you took offence, I'm happy to apologise, as it wasn't my intention to cause offence). I was simply pointing out the utter lack of logic in the argument you put forward. My single comment has already forced you to amend your simplistic view, calculation, and concluding figures. But even then, your argument doesn't deal with the points made by golf charlie, Sandy S, and me elsewhere on this thread and on the UHI thread that I set up a while back.

The adjustments relating to UHI are bogus. The arguments used by the alarmists in relation to UHI are mutually contradictory. The figures they use don't make sense. We have no clear categorisation of the number of UHI-affected sites used in the global temperature datasets.

Oct 22, 2016 at 8:45 AM | Unregistered CommenterMark Hodgson