Leeming WMO03257 – Lost in the heat haze.

54.29701 -1.53299 Met Office CIMO Assessed Class 2 Installed 1/1/1944

When starting this report up some weeks ago, I was asked by a friend of my daughters (28 years old) where I was writing about. I told her “Leeming” in North Yorkshire to which she replied “Oh what’s there then?” I suddenly realised that names that I was familiar with (and almost certainly most of my older readers) meant nothing to most people, especially younger ones. What’s in a name came to mind. But if most people were aware of the nature of locations of so many weather stations they might be less than impressed with their likely reliability.

Just like Coningsby, Cranwell, Waddington, St Athan, Leuchars , Culdrose (the list is very long indeed at over 110) if the prefixes RAF or RNAS were put there then many people would realise just how many weather stations actually are at airfields. Obviously all airfields need detailed and immediate meteorological data, indeed the stipulated quality of siting and instrumentation at major airfields is far higher than any CIMO or standard Met Office regulation thus most do not actually rely of the Met Office unit and use their own separate sensors.

The important issue, though, is that these sites were never intended for “Climate Reporting” purposes and realistically most (if not all) are unsuitable for that purpose. RAF Leeming is a fully operational front line airfield of major importance.

Firstly a modern day wider angle image with the red kite marking the screen location. Google maps and aerial images automatically orient north to the top. Even disregarding the taxiways and runways this site has very significant urbanisation effects running from north east around to south-southwest, the rest being the regular RAF “A Frame” of runways.

Closing in, however, reveals far more immediate problems.

Do the Met Office and its meteorologists not consider almost half a million square feet of concrete parking apron alone (delineated above) might just possibly be somewhat unnatural and could regularly modify temperature readings in a way not representative of the surrounding areas?

Bearing in mind the Met Office rate this site as a fully accurate Class 2 so does it stack up to the 30 metre “exclusion zone”? Below are 100 and 30 metre radius circled areas.

Yes of course it does, the Met Office tape measure certainly could measure out the traditional 100 feet clearance. The Diversion/settlement tank (that was conveniently overlooked at Cranwell) would/should have ruled out class 1 along with the extensive apron concrete but the Met Office no doubt feels Class 2 is justified. Until of course you consider what goes on that apron. Multiple historic images show aircraft quite reasonably parked there – it is after all why it is there – but perhaps the most damning are the helicopters.

Whilst fixed wing aircraft may move away under low power to the runways, Helicopters take off and land vertically. I am often accused of being overly sarcastic but really can the Met Office not see this may be quite an issue? As at Shawbury, Culdrose, Gosport and so very many others, Rotor Wash is a major issue unquestionably liable to hugely distort readings. For those who may think I am exaggerating there are many online videos demonstrating the severity of the effect. Firstly try this short clip:

The rotor wash effect hits the aircraft a timed 30 seconds later though they can actually last up to 3 minutes in extreme. Platinum resistance thermometers used on Met Office settings sample temperatures every once every 15 seconds with 4 readings averaged to produce 1,440 minute by minute readings per day. Met Office daily averages (“Means”) are the product of the maximum plus minimum recorded divided by 2 – as brutally simple as that. Just one helicopter movement over the screen per day can hugely affect the maximum reading for that day and hence elevate the mean. In the past the traditional LIGT with its much slower response times may possibly not have been affected or by very little in that time frame.

This Facebook video below shows the real world ground effects of rotor wash from a quite modest sized helicopter – imagine the effect of blasting the screen with air warmed in the sun from almost half a million square feet of apron alone.

https://www.facebook.com/watch/?v=393345102527299

In addition there are also the effects of all those aircraft movements. Leeming has a relatively “short” main runway, which at 2,291 metres (7,516 feet) does not even make the top 25 of the longest runways in the UK. It does not handle the large transport aircraft that the likes of Boscombe Down (3,205 metres/10,515 feet) and Brize Norton (3,050 metres/10,007 feet) do, rather it primarily handles medium and smaller attack aircraft with a larger number of individual aircraft movements.

Again despite whatever the likes of “Professors” may claim in a BBC article such as this: {my bold}

“Planes make a negligible difference,” says Professor Williams. “Every time you use energy – whether it’s from a plane’s engine, or even just switching on a light bulb or taking a shower – it’s eventually turned into heat. “But all of that is a minor influence compared to the effect of the urban heat island.”

I will call that out as rank nonsense. Perhaps, Professor Williams may wish to stand in the vicinity of the screen when the aircraft (from the headline still image) takes off as in this clip below. He can then try to assure me there is no effect on a PRT……..provided he can see it through the heat haze.

As ever if anyone wishes to add to or criticise my opinion here please feel welcome to engage. On balance though I find it almost improbable to regard the vast majority of post WW2 aviation sites as providing reliable readings for climate historical purposes.

Source: https://tallbloke.wordpress.com/2026/01/11/leeming-wmo03257-lost-in-the-heat-haze/