Castlederg WMO03904 – Coldest or a Constructed Hottest?

54.70708 -7.57746 Met Office CIMO Assessed Class 5 Installed 1/1/1963 as Rain Gauge only, Archived Temperature data from 1/1/1995.

Should the Met Office be attributing national temperature records to CIMO Class 5 sites with a known likely inaccuracy due to siting of up to 5°C? Screen locations that are so poor that they effectively have no site requirement conditions at all imposed upon them at all that are far too common in Northern Ireland.

Amazingly Castlederg has managed to record the highest ever temperature in Northern Ireland PLUS the coldest ever temperature. How has this remarkable achievement been managed?

A 50°C range from minus 18.7°C to plus 31.3°C for the temperate maritime Cfb Koppen climate classification of Northern Ireland in the same exact location is so remarkable it warrants further investigation.

At this point it is worth noting that this site has only been recording temperatures since 1995 and not the quoted installation date in the Met Office publicly viewable data archive. It is quite common for previous rain gauge only sites to have recently added screens, the impression of longevity of overall records (i.e. including temperature readings) is not correct. This becomes relevant when Met Office broadcasters make claims via the BBC such as: “The number of days we see over 30C during summer has vastly increased in recent decades compared with the early 20th Century as a result of climate change.” {My note – why can’t journalists find symbols on their keyboards like this “°”}

Clearly Castlederg was not recording readings before 1995 so any comparison of this site (and all other modern ones) with the first quarter of the last century is completely bogus as an indicator of anything other than the changing locations of screens, different metrology, and urban growth. A classic example of motivated reasoning from the Met Office and a possible explanation of accepting inaccurate Class 5 sites such as Castlederg to “prove” their argument.

However, there is much more to these records than initially meets the eye. Tim Channon reviewed this site in 2012 correctly assessing it as a lowly Class 5. Note the lack of up to date aerial imagery and resorting to monochrome in his original report.

WMO03904, Castlederg, Northern Ireland

The December 2010 cold record is unsurprising – that December was the coldest in the CET for over 100 years and the entirety of the UK &.NI experienced extreme cold. Somewhere in Northern Ireland would record the coldest and that just happened to be Castlederg. What is odd is the high reading from July 2021 from such an apperantly shaded site….or is it?

The headline image is the most up to date one available from either Google or Bing maps and I authenticated the date taken to April 2021 (three months before that record high on 21st July) from Google Earth Pro. Has the site subsequently changed much?

“Having worked with NI Water for many years, the firm {Lowry Building & Civil Engineering) harnessed its knowledge and experience of the water industry and its processes to deliver a high-quality build, with construction commencing in May 2021.”

The Castlederg Water Treatment Works became a huge construction site and what looks like a small plant turned into this below. It is not quite possible to make out the screen as it is surrounded portacabins, cars and general major construction site paraphernalia.

It would probably have been reasonable to suspend taking readings from the station whilst such major works were being completed around it but, as has been demonstrated many times with the Met Office, they rarely ever seem to. Even constructing a solar farm around Chertsey Abbey Meads did not deter them from continuing taking readings.

So how questionable is that 2021 record when no other parts of the UK recorded any notable highs? For my part I simply cannot accept that such a dubious record could have been validated but, as was exposed at Faversham , nothing stops the Met Office in its pursuit of records and “hottest evah!”

Source: https://tallbloke.wordpress.com/2025/01/01/castlederg-wmo03904-coldest-or-a-constructed-hottest/