Exeter Weather Stations – and why is Devon so popular?

Exeter No 2 50.73717 -3.40580 Met Office Assessed CIMO Class 4 & Satisfactory Installed 3/11/2009

The main Met Office CIMO assessed weather station in Exeter is now Exeter No 2 pictured above. Tim Channon reviewed this site and was somewhat scathing about such a modern station with a poor location. I am not an aviator but I believe Tim was experienced in this area, however, when I read terms like “jet blast area” I start to question site locations.

WMO03839, Exeter Airport

How have things developed since?

Firstly, as Tim conjectured, if use of the airport increased and larger aircraft were used then taxiing to the main “long” runway could become an issue. Aside from Covid periods, the number of longer range flights has indeed increased with substantially more flights to the Canary and Balearic Islands. These use Airbus A320 size aircraft operating over the full 6,811 feet runway length.

The right turn from the taxiway onto the east end of the full runway length will inevitably direct the engines exhaust onto the Stevenson screen similar to the effect demonstrated at Dyce (Aberdeen Airport). The Met Office never seems overly concerned about such issues and simply assess the site as a lowly Class 4 – inaccuracy by siting of 2°C – Class 5 seems more appropriate given the likely regular engine exhaust induced distortions. A wider view image, including all taxiways and runways, better shows the implications.

Exeter No 2 though is not the only weather station in the locality, the original Exeter Airport site still operates. Its data does not contribute to the historic record and is used solely for aviation purposes. Many airport sites are correctly not used for climate recording purposes e.g Lakenheath, Mildenhall, Biggin Hill etc. It would probably be more realistic if the Exeter No 2 site was similarly discounted.

But it obviously does not end there with Exeter, after all a certain meteorological organisation has its Headquarters there. Other weather “sites” also exist in the City such as at the University, Weather Centre and even the interesting concept of the “SurfaceNet”

Clearly the presence of the Met Office has a strong influence on Exeter but surely not the entire county of Devon? Whilst Devon is, by area, the third largest English county just behind sizewise the original border areas of Lincolnshire and barely half the original county bounds of Yorkshire, it retains a surprisingly high number of weather stations as well as a number of quite new ones.

Berry Head (Class 4 from 1993), Bratton Fleming ( 3 & 2021 ), Chivenor (3 &1943), Dunkeswell Aerodrome (3 &1964), Exeter Airport No 2 (4 & 2009 ), Hemyock (4 & 1965), Holne:Priddons Farm (4 & 2019) Huntsham (5 &1964) Lapford (4 & 1994) North Wyke (2 & 1965) Okehampton (4 & 1991), Plymouth Mountbatten (4 & 1920), Plymouth:Kinterbury Point (n/k & 2022) Slapton (4 &1960), Stoodleigh Dryhill (4 + 2023), Teignmouth (4 & 1903), Virginstow (5 & 1976)

Contrast these 17 stations to just 8 in the larger old boundary area of Lincolnshire, 7 in the meteorological important county of Kent for south easterly continental air flows, and a mere 3 in the strategically important county of Fife. As was demonstrated in the case of the preponderance of sites to the west quadrant of London (en-route to Reading?) there are 11 stations in one compressed area that do not readily appear to be essential to keep even area representation for the historic climate record.

None of this quantity of Devon stations achieve Class 1 status and the only Class 2 site (at North Wyke) is courtesy of the quality diligence of Rothamsted research who runs the site. Several sites are in very close proximity to each other notably the new Stoodleigh being just a few kilometres from Huntsham, Hemyock is just a short distance from Dunkeswell and both Lapford and Okehampton do not seem to offer anything that North Wyke (between the two) does not already do much better.

I personally have no problem with multiple weather station sites providing they are of good quality and in representative locations. I suggest the abundance of Devon sites does not reflect good quality representation and is only likely to distort the historic temperature record.

Source: https://tallbloke.wordpress.com/2024/10/21/exeter-weather-stations-and-why-is-devon-so-popular/