Abergwngregyn – Completely new or a retread of a former site? A further sign of sample selection.

Checking the full listing of Met Office manual and automatic synoptic and climate weather stations shows no weather station called Abergwngreyn. Checking the full CEDA archive finds no such station. Googling Met Office+Abergwyngregyn directs either to the headline “extremes” page or the forecast for Llanfairfechan. Notably there is no Met Office weather at Llanfairfechan either – more later. Trying to ascertain where this mysterious “new” site was led me to further evidence of site selection to manipulate area representation and also (for me at least) one of the most ironic descriptions of a weather station I have come across so far.

A first point to make is that there is a very, very strong preponderance of newer weather stations appearing in these “Daily extremes” listings – so much so that it is usually my first indication of a site’s installation. Castle Espie, Bisterene, Cliff Farm, Ardtornish, Dundreggan Rewilding Centre, Nantyglo, Rosehearty, Tomintoul and others are all recent examples of very new and regular star performers . Conversely the vast majority of long established sites very rarely, if ever, appear. I will shortly be reviewing again the data from the relatively new Frittenden weather station which is an incredibly dubious but regular entrant in the regional and national highest temperatures whilst the Goudhurst station established over 90 years ago and just 7 miles distant never has.

Identifying the location of this site was likely to be very difficult given only the village name and nothing else to go on so I started with just the aerial view of the village of Abergwngregyn based on it presumably being near Llanfairfechan in north Wales.

The first thing I noticed was a marker for a place just known as “Aber” ( obviously a remarkably common Welsh place name prefix) and then on further zooming in, the Henfaes Research Centre of Bangor University – an agricultural unit that comments on its automatic reporting weather station. Putting two and two together came up with the very long term sites known formerly just as “Aber” (not to be confused with a Swedish popular music quartet) and, in a new location, the subsequent “Aber No 2”.

A lot of Google “StreetView” kerb crawling finally located the former site Aber No 2 which was in operation until March 2002 as below.

53.23865 -4.014218 No known Met Office CIMO Assessment Installed 1/11/1982 closed 1/3/2002 – reopened unknown

This site was always manually reporting presumably by staff/students at the College. I suspect, but cannot yet prove, that this location has been reopened based on the College making a point about this “automatic” weather station and that the data appearing on the daily extremes page is only from automatic sites. I hypothesise that, as it was formerly only equipped for manual observations and automating may have been difficult for electrical and communications connections just after the turn of the century, the Met office chose to stop using its data. The college itself probably continued use of the screen for their own purposes and only subsequently opted for automation based on more modern equipment being capable of using just a small solar panel and battery pack. I finally found a distant image which AI slightly enhanced for clarity – the 10 metre high wind mast was the confirming landmark.

Considering this site’s coastal situation at the bottom of very significant mountains I guessed this generally mild location would also encounter Fohen Effects . I asked AI whether my hunch was correct.

“Yes—Abergwyngregyn is strongly predisposed to föhn warming, especially during southerly or south-south-easterly airflow. That is a very plausible explanation for its repeated exceptional winter temperatures.

The station sits at only about 15 metres elevation on the northern side of the Carneddau. Immediately to its south, the terrain rises rapidly to summits exceeding 900 metres. This gives it an excellent lee-side position:

1. Moist southerly air rises over the mountains and cools.
2. Cloud and precipitation remove moisture on the southern/windward slopes.
3. The drier air descends steeply toward Abergwyngregyn.
4. Compression warms the descending air, sometimes accompanied by sunshine as the föhn cloud clears.

This can produce a striking pocket of warm, dry air along the North Wales coast while places only a modest distance away remain much cooler. The effect is particularly conspicuous in winter because the descending air can disrupt or replace a shallow layer of cold surface air.

The historical results fit that interpretation very well:

• 18.3°C on 27 January 1958
• 18.3°C on 10 January 1971
• 18.0°C on 18 December 1972

The Royal Meteorological Society specifically notes that Britain’s highest winter temperatures often occur in North Wales and northeast Scotland because these are favourable lee-side locations.“

These noted highs that AI identified were much more frequent than it had quoted especially when adding in its predecessor site “Aber”. I checked with a site that records daily minimums and maximums that I often consult – though I must add that I have had several concerns in the past over its fundamental accuracy and site identification.

The original Aber location was also hosted by the college and from old records lay about 750 metres to the west at the same elevation but has since been developed by college buildings – a common occurrence. This location managed to record a national January maximum high on 4 separate days being the 9th, 10, 27th and 30th in, variously, 1929,1958 and twice in 1971 – not a demonstration of modern anthropogenic global warming by any means in holding records from so long ago. Below is an example extract of these events that caused me so much amusement.

What caught my eye was the record noted for the 24th January being given to Llanfairfechan which as I had previously noted did not have an official Met office weather station. Looking at the footnote to the symbol “Ϯ” alongside the reading states

 “a non-Met Office site but deemed to operate to a similar standard“

Really? A “similar standard” is it that BAD? Quite why TORRO arbitrarily chose to include a private weather station in their listing seems remarkably odd especially as it is not readily visible in any other records I could find. Again though, Llanfairfechan will likely pick up the same Foehn effects as Aber in all its incarnations has.

So this comes back to the site issue. There are several weather stations along the north Wales coast with over half of the days national maximums (16) in January alone credited to north Wales coastal sites with a further 7 in February and 11 in December. No matter how good or otherwise the Aber site is, there have been no fewer than 12 days of winter (December, January and February) with national records attributed to the area. The site effectively closed almost a quarter of a century ago using Liquid in Glass thermomeers that has now, on re-opening, been replaced by instantly recording Platinum Resistance Thermometry. I can almost 100% guarantee that there will now be a regular succession of ever increasing highs and breaking of records from this site – a claim which I will monitor and report on in the future whether my hypothesis is correct or not.

The final point comes down to whether or not such Fohen Effects should be added to the climate record. There are parts of the world described as “Foehn Climates” where these are regular events that shape the entire ecology of the region. However, this is not the case anywhere in the UK. The effect is predominantly around north Wales and northeast Scotland but is very sporadic with lengthy periods absent any events. They are also often very localised effects and from this it often appears the Met office chases such locations to install stations.For example, Achfary in a domestic front garden has only been recording temperatures for less than 20 years but already holds the UK record highest temperatures for both December and January. Given that meteorological averaging gives total domination of averages solely by extremes (whereas most statistical evaluations would naturally exclude the top and bottom small percentiles) the deliberate inclusion of such brief transient effects can create huge distortions. The more sites you add into the mix the more events detected, the higher the “average” increment becomes. The move away from rural inland sites (very unlikely for Foehns) to predominantly coastal sites (highly susceptible) the easier it becomes to move the climate average ever upwards.

The entire subject of statistical and computer modelling of climate history is one that is very easily gamed and there certainly seems no shortage of “scientists” willing to play lucrative games.

Footnote: There is also an automatic weather station in this area operated by the UK Centre for Hydrology at Henmaes Farm which is a completely separate entity – and not subject to Foehns.

Source: https://talkshop.blog/2026/09/12/abergwngregyn-completely-new-or-a-retread-of-a-former-site-a-further-sign-of-sample-selection/