The above is a rare sight indeed as this region’s daily hotspot records are regularly dominated by the atrocious sites at Hull: East Park , Bridlington and the doubled readings by the solar farm at Leconfield. RAF Topcliffe (odd how the Met Office always misses off the RAF description to so many of its locations) sits in the Vale of York and is more known for winter chills than summer thrills. It is also a classic example of how ground cover changes can have dramatic effects.
54.20478 .1.39015 Met Office CIMO Assessed Class 4 Temperature records from 1/1/1947
When Tim Channon reviewed this site in 2012 his measurements indicated Class 2. In fairness if they were the only parameters than Topcliffe would just sneak in as a good site. However, Tim went on to downgrade his estimation to Class 4 (the Met Office concurred) on the extreme level of ground cover change. This is where historic imagery proves so useful, the relentless grass mowing regardless of prevailing weather conditions frequently turns the area into a wholly unnatural almost scorched earth.
The above altered angle view indicates not only scorched grass but also apart from the taxiway the inevitable helicopter landing “H”. Adding in the extensive hangars and buildings to the west transforms the overall site from a rural one to a typically unrepresentative and unnatural aviation site. This, however, fails to show up in comparisons when all the other nearby sites are so similar.
RAF Topcliffe being compared with RAF Dishforth, RAF Leeming and RAF Linton On Ouse really is not a case of “great minds think alike” and much more akin to “fools seldom differ”. Whilst the Met Office may like to think airfields are suitable – “For example, official weather stations are often located at airports as they have plenty of open space making them a good place for observations to take place. However, the observation equipment is set an internationally-agreed distance from the runway to ensure no external factors can influence readings in any way”
Surely it is rather inappropriate to only compare one airfield to another. The last comparison of Hartburn Grange is very remote and also defunct as of 30 years ago. It appears that this entire section of the country is dominated by active or former RAF bases with few otherwise “natural” sites. The CEDA archives have an interactive map of sites which for North Yorkshire centred on Thirsk/Topcliffe which looks like this.
Almost perversely this county has the Class 1 Cawood site but the Met Office does not even seem to want to recognise its long term existence preferring low grade aviation locations. Even more concerning is that 21st Century North Yorkshire has seen the closure of 10 full weather stations at Ravensworth, Ashkam Bryan, Church Fenton, Wyecliff Hall, Dishforth, Harrogate, Kirby Misperton, Linton on Ouse, Middlesmoor and Malham Tarn. In the same 25 year period only Class 4 Pateley Bridge:Ravens Nest and Class 5 Bank Newton No 2 have been installed. The overall site quality is degrading not improving.
This notable reduction in more northern and easterly cooler located stations is in stark contrast to the increase in warmer southern and westerly locations notably west London {contrasted with Derbyshire} and Devon an consequently a distortion to national averages.
In summary the Met Office certainly does not seem to be actively seeking to improve its network. Poor sites such as Topcliffe appear to be far more common that should be to represent the natural climate of their area and little regard is given to the few good locations available. Things really do need to change for the better but under the current regime this seems extremely unlikely.
via Tallbloke’s Talkshop
August 18, 2025 at 03:56PM
Iowa Climate Science Education 