Aberporth DCNN 8008, 8009, WMO 03502 – Another absurd and horrible history…to the 2nd decimal place.

52.13948 -4.57116 Met Office CIMO Assessed Class 4 Installed 1/1/1941 Relocated 31/6/1966

Aberporth weather station is NOT situated at the nearby former RAF Aberporth (now West Wales Airport) but rather at MOD Aberporth which is a long term missile testing range. It was never a conventional aviation site and was a specific weapons testing range site where wind speed and direction was the primary function. Long term “climate” reporting was equally never one of its intended functions and that the site’s data is currently used for that purpose demonstrates just one of the many absurdities in the Met Office’s extensive range of misrepresentations.

Aberporth is one of the sites that the Met Office proffers to the public as a “Climate Averages” station with long term figure (expressed to the second decimal place) for the period 1961 to 2020. In this post I shall demonstrate how this is a known misrepresentation of the data and is thus state sanctioned disinformation.

In addition to the site’s data being used for climate averages, it is also proclaimed as a “Historic Station” with its monthly averages published from 1941 to date.

Firstly, most of the general public would infer high quality from somewhere a government agency declared “Historic”. Very few indeed would expect a standard that their government agency itself owned up to being grossly inaccurate i.e. “Class 4 (additional estimated uncertainty added by siting up to 2 °C)“. However, checking that classification first, I defy anyone studying the CIMO regulation standards to agree with that Class 4 rating.

Bluntly, Is the Met office so self obsessed that it cannot see? Hard standing, cars parked, buildings…is this all supposed to be the “natural environment”? This is the same organisation which discusses temperature increase since “pre-industrial” times – is it not rather obvious that they should not be trying to compare “pre-industrial” temperatures with a heavily “industrialised” modern site? To state the obvious, there were not a lot of cars parked alongside Stevenson Screens in 1864 when Stevenson first designed them……and as for helicopters?

The site history of modern times is one of ever changing surroundings. When Tim Channon reviewed the site in 2012 it was actually worse than now with a building close to the west of the site.

The immediate proximity is bad enough, but then consider the activity at this site. The wider angle view reveals helicopters regularly patrolling the site with take off and landing points. “Observations” are much more concerned with missile testing than of the meteorological temperature taking.

The reality is this is a Class 5 Junk site for “Climate Reporting” purposes with its attendant

“Class 5 (additional estimated uncertainty added by siting up to 5 °C)” however again almost miraculously with all these inaccuracies the data can be analysed to the second decimal place….really?

So how does the Met Office portray its “Historic Data”?

Note the location is specified in detail as….. “224100E 252100N, Lat 52.139 Lon -4.570, 133 metres amsl” So obviously that is where it is located and has been so ever since 1941. Why would any member of the general public even start to query such absolute factual evidence from a government agency? Well I would simply because the Met Office very rarely feel the need to be truthful in such details.

Deep in the archive is this typical note.

1999-10-14

Current

SITE INFORMATION

OLD SITE WAS AT GRID REF 2239E 2520N AND ELEVATION 133M UNTIL 31/6/1966

So the site was NOT in the same location for the entire period. The Met Office gives the “impression” it was in just one location in its “Historic Station” when it definitely knows it was moved in 1966. This can only be defined as disinformation and occurs on most of their Historic Station sites as I have regularly such as at Stornoway, Whitby, Sutton Bonnington, Manston, Wick indeed nearly all of them are similarly misrepresented.

Does this relocation matter? As I have demonstrated multiple times in my reviews, location is key hence the CIMO siting classifications were formulated in the first place to overcome discrepancies in comparisons over time. More specifically South Farnborough No 2 detailed the significant difference even a small relocation made.

Where was this previous site? The given coordinates are not really good enough to pinpoint the exact location but luckily some very old records were unusually helpful together with a bit of Grok AI “deep thinking”.

Again the Latitude/Longitude given is only of limited precision and the over-written “Nat Grid” reference did not mean much to me so I ran it past AI to see if it “knew” something that I didn’t. Surprisingly Grok directed me to an obscure and outdated RAF shorthand for grid references and offered me enough details for me to compile the map below for where it was in relation to now.

I cannot be 100% certain as I am trusting Grok AI, however, other circumstantial evidence indicates a long term set of weather sensors at this original location that appear to be still operational. This original site would have been more appropriate for both its weapons testing functions as well as likely giving significantly better temperature indications in being much less contaminated by extraneous effects. The pathway to it does suggest continued use and that this may be the weapons site’s prime data source to this day. The newer and inferior modern Met Office site looks to have been located for regular observer’s convenience rather than any genuine meteorological reason.

So far we have a poor modern site. The original site is not being credited hence the “Historic Data” is from two distinctly different datasets with the modern site being prone to over-record. Is there any more conclusive evidence that the Met Office knows this? The archives quote two different District County Network Numbers (DCNN) for this site as 8008 and 8009. Why?

“3.6. Station identification

Over time certain instruments, or the whole enclosure, may be relocated some distance away from the original site. Where the distance moved is small, the observations obtained from the new site may have exactly the same climatological characteristics as previously and it makes sense to regard them as coming from the same source or station distinguished by certain identifiers. Where the distance moved is large, or, where the exposure at the new site is sufficiently different that a detectable impact on the measured climatology is judged likely, it is appropriate that observations from the new site are labelled by a different set of identifiers.“

The station was renumbered (“a different set of identifiers”) which is a clear indication the new site represented different climatologogical characteristics and that the new renumbered site was definitely not the same as the old one. Despite this difference the Met Office have simply transferred the data to the same archived file as shown here with the changeover of DCNN 8008 to 8009 in just one day with no overlap comparison period.

If this is not poor enough, go back to the manuscript temperature readings from 1956 accurate to 0.1°F equating to 0.055°C. The Met Office transcription to their files recorded in degrees celsius hits their bizarre double rounding protocol as detailed in my review of Wye. Any organisation that can routinely convert data scales creating errors over an order of magnitude is disgraceful. A I previously stated,

“A diligent and well trained observer has taken accurate historic readings for these to be, for want of a better word, “botched” by a likely bored intern/transcriber.

This is an example effect of this treatment: 34.4°F is originally recorded. This is rounded down to 34°F then converted to Celsius as 1.1°C. Alternatively 34.5°F is originally recorded, this is rounded up to 35°C which converts as 1.65°C again rounded up to 1.7°C in the archives.

Thus in the above example, a reading difference of just 0.1°F ( 0.055°C) ends up as a recorded difference of 0.6°C………………. an eleven fold error factor. And this happens throughout the whole temperature range.“

To put all the above into context, imagine a private business trying to sell a product. They are claiming standards that they are not getting anywhere near to achieving but riding off the back of a former good reputation long gone. They are falsely claiming premier quality based on tampering with historic reviews. They convert reported data to another scale massively distorting the numbers in the process. You are compelled to pay them for doing this whether you want their product or not. And if you question any of their claims you are branded as a “misinformer” and they attack you.

This cannot be allowed to continue.

Source: https://tallbloke.wordpress.com/2025/11/04/aberporth-dcnn-8008-8009-wmo-03502-another-absurd-and-horrible-history-to-the-2nd-decimal-place/