Camborne WMO03808 – What should be an exceptionally good site strongly indicating worrying signs. Plus more risible Met Office May Madness.

50.21830 -5.32764 Met Office CIMO Assessed Class 2 Installed 1/1/1978 (Despite false claims of earlier dates)

Camborne is one of the most sophisticated sites the Met Office operates with the entire suite of meteorological observations both surface and atmospheric. I would have expected this to be an exemplary site and as I noticed it was rated (perhaps surprisingly) as Class 2 ( I thought it was certain to be Class 1 just on reputation) I had chosen not to study it earlier. so it came as quite a surprise to find a lot of things were not as I would have expected.

When the late Tim Channon started the original Surface Stations Project his primary aim was to identify and assess the standard of weather stations to the CIMO regulations. This was in the days prior to the Met Office’s own assessments being (very reluctantly) made available to the public. Though many of Tim’s original assessments were brief, on others he expanded in great detail, one such being Camborne which I recommend reading first as below.

WMO03808, Camborne

Tim was an extremely qualified engineer and former RAF man and certainly knew what he was detailing in great depth. He rarely called the assessments wrong so when I read his somewhat disparaging views and lowly rating I felt obliged to dig deeper and offer more information. Tim called Camborne Class 4 and that really is not a good look for such an expensive flagship site.

First to clarify site provenance (for my purposes of the reconstruction of an historic climate record) I felt this would be straight forward as this must be a very long term site – mustn’t it?

“Since 1875” looks very convincing but is completely WRONG as so much in the annals of amateur meteorology actually is. There are no official records for Camborne from anytime other than the latter half of the 20th Century.

And then it gets worse because even the Met Office themselves get the start details wrong. Below is the listing of manually recorded climatological returns in the CEDA Archives.

So now the earliest real date for Camborne is shown as 1953, however, if you actually dig deeper still the question becomes “When is Camborne not Camborne” ……answer …”When it is Rosewarne EHS” which is a completely different place, different coordinates, different elevationand different instrumentation and standards.

Rosewarne Experimntal Horticultural Station was part of the “EHS”service – a similar body set up in post WW2 Britain to the EHF service at High Mowthorpe. The Rosewarne EHS weather station ran from 1952 to closure in 1989 and is a completely different entity to the Camborne Met Office station despite confusion over naming which is a regular feature of Met Office archives such as I noted at Valley and several others.

The reaIity is that Camborne first came into being with any form of archived data from 1978. Any prior readings expressly do not relate to the current location nor anywhere particularly close to it. Suggestions of any form of official or reliable readings for the preceding 103 years are not supported by any facts whatsoever.

Regarding the current state of the site, Tim’s assessment is spot on in the exact meteorological definitions of the CIMO regulations and Class 2 does look potentially questionable using his evidence dating from 2012 ( and earlier) imagery. The ever changing and unnatural ground cover does unquestionably breach standards for Class 2, the enclosure paving is a debatable issue, and there are intrusive levels of artificial paving within the defined “exclusion” zones”.

On these technical points above I cannot argue with Tim’s verdict, but to an extent (given how bad most other sites actually are) I did feel Camborne may well be “good enough” to validly use its observations for the last 50 years ……..until Met Office May Madness made me look deeper still.

Those who follow my X profile will be aware of the low regard I hold the “Media Advisor & Senior Operational Meteorologist UK Met Office” Marco Petagna. Whilst he opts to snipe at the likes of “contrails” protagonists he refuses to respond to any of my questions or comments – almost certainly as he is not allowed to. However, after over 460 very well read online posts on his “specialist subject” I do feel I qualify as a significant element of the media. Even the broadsheet Washington Times has run an editorial on the Surface Stations Project and its findings. But here is the standard of Behavioural Insights Team controlled twaddle the Met Office and Petagna heavily promotes.

Camborne is 87 metres/ 285 feet above sea level and (should be) in open countryside. This high minimum temperature is indeed very surprising at this Cornish site just 2.55km/1.6 miles from the open sea. It becomes more surprising when one sees nearby private weather stations recording these sorts of temperatures below. Barely over 15 °C just 4 miles away from Camborne begs some serious questions.

What could cause such an anomalously high temperature at Camburne when even nearby official station RNAS Culdrose (with its huge areas of heat absorbing runways, taxiways and aircraft parking aprons) did not hold up anywhere near as high neither? One option would be a well known artefact of Aitken Effect that Stevenson Screens suffer from. In very low wind speedthe air within the screen can become stagnant and overheat. With no ventilation to “refresh” this entrapped air the screen itself can insulate the contents and artificially hold up overnight temperatures. Realistically this should not happen very frequently unless of course even well exposed screens are compromised in some way. What was that Tim said;

“Site is neat and tidy, wind tower off to the left, radiosonde hut and launch area in front of you, main offices centre (presumably gas heated, tank on the north side) . A chain link fence divides from the field, narrow field margin, in front of you is a very common plant on poor soil (Ulex europaeus, gorse, common gorse, furze) and other things. As near coastal substantial trees are rare, but in my experience of similar locations this is somewhat protected from severe winds which will produce a turbulent boundary layer even under severe storm.”

Later he added

“There is a different problem with chain link: it is notorious as a plant support, they love it, all too easy to end up with a wall of vegetation. This should not be a problem at closely maintained sites: I don’t recall seeing this trouble at any of the other sites but few have photos, vegetation outside the enclosure seems to be an altogether different matter.

Poor site maintenance is a problem I have encountered at literally over 100 sites and I regularly feature such problems notably at Glasgow Bishopton and Cromer A graphi of Tims’s chain link issue at Bishopton,

What about the wider surroundings to Camborne – spot the screen? You can just make out the very top of it peeking above the now vastly grown hedge from Tim’s research days.

To put this image into context it is taken from the road to the west, now study the site close up with north to the top.

The Camborne screen is effectively shielded at ground level from any wind by both a likely 2 metre high hedge and then a chain link fence of whose maintenance quality control we have no means of confirming. And the wind speed fell that night at 10 metre level to just 2kph ( or just 0.5 3 metres/second) at times – there will have been no perceptible wind inside the enclosure let alone inside the screen.

In conclusion whilst I started a little sceptical about Tim’s original assessment I now concur with his view that this is not a reliable site and demonstrates poor site husbandry by the Met Office. The now “record” 3rd day in a row of “high minima” is just more evidence to support the growing proof that the Met office is more concerned with proving a theory with any numbers it can whether they are accurate or not.

Source: https://tallbloke.wordpress.com/2026/05/27/camborne-wmo03808-what-should-be-an-exceptionally-good-site-strongly-indicating-worrying-signs-plus-more-risible-met-office-may-madness/