Corgam DCNN 8074 – “This station provides data for an agricultural business.”

52.22277 -4.08031 Met Office CIMO Assessed Class 4 Temperature records from 31/5/2018 – current operational status uncertain.

Corgam is a manual reporting weather station to the north east of Lampeter in mid west Wales which was only installed in 2018 and its current operating status is peculiarly uncertain. The reasons for its installation and subsequent operational history are somewhat odd and seem to represent a very casual approach to Meteorology by the Met Office itself.

Firstly this low grade assessed Class 4 site is under 3.5 miles from the long standing automatic Swyddffynnon weather station operational from 1955. This very sparsely populated area of south west Wales already had numerous long term sites as demonstrated by this map showing only automated sites. The site above Tregaron showing “17” is Swyddffynnon with both the high quality Trawsgoed just north of it and Gogerddan just outside Aberystwyth. Corgam is just to the south west of Swyddffynnon.

The Met Office produces a list of all its CIMO assessed weather stations here with Corgam clearly shown as one of its “Climate Stations” intended to be representative of the wider area climatic conditions.

This webpage specifically states the following purposes of manual reporting “Climate Stations” as below

“The map shows the current network of automatic (synoptic) and manual (climate) stations covering the UK.

UK weather stations report a mixture of snapshot hourly observations of the weather known as synoptic observations, and daily summaries of the weather known as climate observations.

For instance, hourly temperature is a synoptic observation, but daily maximum and minimum temperature are climate observations; cloud is synoptic but sunshine is climate. Climate observations are made at 0900UTC, with some stations making further climate observations at 2100UTC.  In summer these correspond to 1000BST and 2200BST respectively.

Observations from around 260 UK automatic (synoptic) stations are collected in real time; climate data from these stations also comes in straight after readings are taken. Climate observations from around 140 co-operating observers at manual climate stations are also received in slower time.

All climate stations record daily maximum and minimum air temperature and rainfall amount, recorded over the period 0900-0900UTC (1000-1000BST in summer).”

I feel that is an extremely specific definition of the purposes of a “Climate Reporting” weather station, so how does that sit with this detailed description of the site.

Pause for thought………..the Met Office is basing its reports on “Climate Change” ( noted to the second decimal place of a degree) based on data from a site described as “This station provides data for an agricultural business.” So presumably that is “Near enough for Jazz” as far as the Met Office is concerned? I have no wish to in any way disparage the, no doubt, meteorologically interested amateur running this site, however, the British public are being led to believe in the high quality of the Met Office station as detailed here.

https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/research/library-and-archive/library/publications/factsheets/factsheet_17-observations_over_land_2023.pdf

Just one example:-

“Wind
Wind over the land surface should ideally be measured at a height of 10 m above ground level at the top
of a mast or some other supporting structure that has small impact on the local flow of air. Wind is the
horizontal movement of air and is specified by its speed and direction. “

Okay how does that square up to the reality of –

“Wind gauge is mounted on a 2 metre pole above ridge of farm building which is itself approx. 6 metres high.“

THIS IS COMPLETELY UNACCEPTABLE ON THE PART OF THE MET OFFICE .

The function of a climate weather station is to take timely and accurate readings. Clearly any wind recordings, if taken, are junk. The site itself is generously assessed by the Met Office as Class 4, frankly ,without wasting too much time, it really is not. The Ordnance survey sheet shows a significant sloping gradient, the screen is subject to shade and the whole site is a working farm with no enclosure at all to the screen.

Moving onto reading regularity does not indicate recording temperatures was a priority. The site started 1/6/2018 and of the 214 days readings failed to provide both tmax and/or tmin on 10 occasions meaning 10 days where no daily average was possible to derive. 2019 there were only 321 complete days, 2020 – 340 complete days, 2021 just 249 days , 2022 just 284 days. In 2023 all readings abruptly stopped on 1/10/2023 having only managed 260 readings to that point. Whether or not the site is still officially reporting is open to question though it has not been deleted from the listings noted above. This lack of readings does not, however, restrict the Met office from deriving “annual daily means” from sites as demonstrated by the absurdity of deriving an annual daily mean from Mickleham (and others) from tiny fractions of annual readings.

A slightly ironic aspect of my research into individual sites is that I occasionally discover the site owner’s identities such as at Whitechurch. In the case of Corgam I unintentionally stumbled across the owner/observer on “X” (formerly twitter). I have no wish to identify them or criticise their efforts but it certainly seemed that, whilst they held an interest in meteorology for their occupational advantage, it was not an over-riding interest of theirs for their unsuitable data to be used in the construction of a national historic temperature record. The Met Office is solely to blame for the inclusion of this unacceptable climate reporting station.

Source: https://tallbloke.wordpress.com/2025/06/19/corgam-dcnn-8074-this-station-provides-data-for-an-agricultural-business/