52.16272 1.27962 Met Office CIMO Assessed Class 3 Temperature records from 1992
Charsfield weather station is quite a rarity in being CIMO rated Class 3, less than 8% of Met Office sites meet that standard and many that supposedly do, really do not, such as Heathrow and Charlwood. This is a long term rain gauge site operating from 1906 and presumably relevant for the nearby Potsford Brook. This is quintessential East Anglian countryside ( near Woodbridge) and numerous “English” pastoral setting films and books have been based on this area notably “Akenfield“.
In reviewing many weather stations I do feel it sometimes comes across that I am being overly critical. I make no apology for that as it is more important to be accurate than polite. In the case of Charsfield, I also have to admit to a personal affinity for the likes of the site’s owners whose endeavours, in my purely subjective opinion, are vitally important to the nation’s overall well being. These people have a remarkably difficult, but essential, job running both an arable and fruit farm.
This BBC article highlights both the farm and the varying difficulties they encounter throughout the season. It is very noticeable from the article that the farmers blame the water authorities directly for lack of storage for not allowing irrigation as and when required and do not resort to some amorphous blaming of “Climate Change”.
Looking at the site, firstly it is only a very gentle slope down to the brook so there is no issue there, the site is as flat as required. Proximity to unnatural extraneous heat sources is unlikely despite no visible enclosure. The 30 metre radius circle exclusion zone for Class 2 looks as below.
This must be a very narrow fail for Class 2 and largely based on the shrubs/trees to the south west. The low hedge to the north west is also not good but not overly detrimental from purely a solar radiation viewpoint but is a potential windbreak.
So often with these rural sites, the Met Office seem to employ very strict standards that do not seem to be applied in other more “favoured” urban locations. For example how would Charsfield compare if suddenly surrounded by a solar farm as at equally claimed Class 3 Chertsey Abbey Mead – {just look at how high those solar panels shown in the video clip actually are}.
Is the Met Office really claiming Charsfield is no more accurate than an enclosure being surrounded by jet blast screens and plastisol cladding viewing blocks on the perimeter of one of the world’s busiest airports?
Charsfield also has a very good manual observations record up to 22/06/2008 though it appears there were some problems with the conversion to automatic reporting that were only resolved 5/11/2010 whereupon normal reliable service was resumed.
In this report I hope I have stuck a balance between the subjective and objective views. My gut feel is that I certainly trust less fashionable Charsfield more than certain other, allegedly, equal quality sites in the Met Office’s “eyes”.
via Tallbloke’s Talkshop
August 22, 2025 at 02:04PM
Iowa Climate Science Education 