Special topic – UHI and why location matters.

The topic of whether or not location of weather stations is relevant has been raised with me several times. Both online posters on X and pseudo-scientific “Fact Checkers” have assured me that I don’t have a clue what I am talking about. For example, the relocation of Stornoway station from Lews Castle to the nearby airport and subsequent splicing together of historic data could not possibly make any difference as it was all the same “air stream” according to one, no doubt, “erudite” poster. Interestingly, even supposedly highly qualified “Climate scientists” make comments in a similar vein that are equally misguided. Rather than simply discuss the issue theoretically I felt visual graphics of real time readings would be a more appropriate way to demonstrate the point that location matters.

I have screen-captured sections of the Weatherobs images from 19:40 to 20:30 28th February 2025. These show live hourly temperature readings from automatically reporting Met Office stations and include some that are official sites but not CIMO assessed for climate reporting purposes.

The headline image of west London shows the Battersea site (Class 5 just west of Brixton) reading 9°C whilst simultaneously Kew Gardens ( Class 2, north of Richmond) was reading 5 degrees colder at just 4°C. Moving further west, Heathrow (Class 3) rises again by 3 degrees to 7°C but just barely 3 miles north west at Iver (Class 5S) it again falls 3 degrees to 4°C.

It is beyond any reasonable debate that these above variations are not in any way representative of natural phenomena. Clearly these represent the known Urban Heat Island effects identified by official research. The sudden temperature increase surrounding Heathrow demonstrates the result of locating one of the world’s busiest and largest international airports there. There really are no otherwise natural reasons for the scale of increase but that does not seem to deter “climate scientists” from claiming otherwise.

https://www.bbc.co.uk/news/uk-44980493

“Paul Williams, Professor of Atmospheric Science at the University of Reading.” is the expert called by the
BBC to justify the anomaly of Heathrow. “Planes make a negligible difference,” says Professor Williams. {talkshop comment – this claim will be subject to separate detailed scrutiny in a future post} He then goes on to explain the UHI effect thereby demonstrating that such urban sites are expressly NOT SUITABLE for inclusion in the national historic temperature record.

Somewhat, perversely he then goes on to compare temperatures at Heathrow with Kew – “If you compare Heathrow to nearby Kew – which is eight miles away – there is hardly any temperature difference between the two.” Well I just have compared them above and there very blatantly is a major difference. For any one claiming this is a “cherry pick” I suggest they check out Weatherobs on a regular basis (as I do) before making that suggestion. Additionally notice the graphic is headed “Average Monthly Temperature” – I strongly recommend reading the following short guide available free online for context.

All the above demonstrates – with full admission by those claiming competence – that the London areas are totally unnatural. This really should come as no surprise to anyone. The question of whether such large variations can be caused simply by poor siting in other parts of the UK is also equally demonstrable. Just to the west of Evesham in the image below are Pershore and Pershore College (used in the current CET) which are sites just over 3.5 miles apart at the same elevation.

Is it genuinely realistic to consider that two sites at the same elevation and so close together should have such a large differential of 3 degrees? Clearly the location does matter. Switching over to just east of Milton Keynes, what natural effects would be making the 4 degree simultaneous difference between the Rothamsted Research owned Woburn station reading of 1°C with the Cranfield University 5°C reading? Is it somehow not rather probable that the airfield location of the latter makes a significant difference to the open country location of the agricultural research centre at Woburn?

All around the country there are stark contrasts between readings of sites in very close proximity that cannot be registering natural variations.

Amesbury above has both Boscombe Down airfield weather station just a few miles from the Larkhill site which sits adjacent to a 2,400 square metres sand school. The latter well drained and obviously unnatural area of sand loses heat rapidly as demonstrated by the above 3 degree colder temperature difference. It will also warm up much quicker by day to a higher temperature with, no doubt, the “average” daily figure becoming a classic case of the “arithmetic mean-ingless” .

Moving to the East Anglia region, the 3 degree differences from inside and outside Cambridge are an obvious UHI effect. The 4 degree differential from the “topsy turvy” Santon Downham to RAF Mildenhall is due far more to the inappropriate localised effect at Santon Downham than any likely airfield effects.

Are there naturally 3 degree differences in the country side just south of Lincoln or are the airfields at Waddington 6°C with Cranwell and Coningsby both showing 3°C all displaying artificial influences.

The real time major variations between sites in close proximity and elevation with no otherwise natural differences demonstrates that siting is critical to representation of the wider area. That there are so many major variations shows the chosen Met Office station siting ( primarily for immediate weather forecasting) is not appropriate for long term natural change comparisons. Only selected sites free from artificial compromises should be used for historic temperature recording. The objective of the Surface Stations Project is to identify those suitable locations.

Source: https://tallbloke.wordpress.com/2025/03/01/special-topic-uhi-and-why-location-matters/