Marham WMO 03482 – A cautionary example of how deceptive Met Office records can be.

52.65132 0.56609 Met Office CIMO Assessed Class 3 Installed 1/1/1951 (Digital archived temperature records only from 1/1/1957)

When Tim Channon assessed this site in 2012 he correctly assessed it as a marginal Class 3 not quite making Class 2. The 10 metre and 30 metre radius circles above show it just fails the better category on slightly more than 10% hard-standing within the 30 metre zone though had the Met Office claimed Class 2 it would have been a tough one to argue with without a detailed on site inspection. RAF Marham was established in WW2 thus the site has a longstanding record (according to the Met Office at least) so this should be a reasonable candidate for long term climate averages – until the site history in studied in forensic detail.

Why should anyone dispute the sort of detailed data supplied by a government agency and so beautifully presented as this below.

The second decimal place “accuracy” of even tiny units is impressive. Given that the human naked eye cannot discern less than one tenth of a millimetre – those 10µm monthly rainfall differentials must be very “scientific” and important to establish. Is any of the above really accurate at all though? Any representation of a genuinely scientific data set must have certain important key factors – undisputed accuracy and consistent reliability of the raw data to be analysed. “Near enough for Jazz” is a term not even jazz musicians use.

The CEDA archived data shows an installation date for the Marham site of 1/1/1951, however the downloadable digital temperature records only start from 1/1/1957 and ALL of those from then on show the coordinates of the current site and not where it actually was {an important point to remember}. An issue I often emphasise is why should anyone question the “official” record – certainly no modern day student would. The climate averages show 60 years worth of warming thus the “science is settled”. For “swivel eyed loons” like myself I tend to dig deeper and when I do some surprising things come to light.

So now we have established that temperature records do exist from 1951 onwards but have simply not been transcribed (and thus not adjusted by converting from Fahrenheit to Celsius) into the digital archives. Being written at the time they also show the original location and NOT the one quoted on all the digital records. So where was this original location for the Stevenson Screen?

The original site at 52.648382 0.569747 also had a different identifier number of DCNN 3024 indicating a different climatology under Met Office site numbering rules. Not only was it located over 400 radial metres from its present location, historical images show a severely compromised site with buildings and road ways surrounding it. – Class 4 or even 5 was more appropriate.

Re-locations did not stop there. The original location ran from 1/1/1951 to 30/11/1966 thus most of the first 6 years of that 60 year climate average data came from the original site which then closed. The replacement site does not have any data at all until 1/8/1969 almost another 3 years completely missing. This is where it went to.

52.654856 0.5502923 and without a shadow of doubt this would have been yet more class 5 Junk. How do I know that? Well Google historic imagery indicates those buildings and car parking predated the site’s time there. This relocation was very significant indeed being almost exactly 1,500 metres from that 1951 first site.

Readings were taken from this site from 1/8/1969 to final relocation to the present site in 1982 moving this time 1,120 metres (and those 410 metres from where it originally started.)

However it does not just stop with these three completely undisclosed re-locations over varying altitudes and completely different climatology, the frequency of readings and recordings also changed over time. For reasons not explained anywhere I can find, archive readings regularly changed from once a day to twice daily and back again. This has a relevance as described in my review of Lerwick where readings can be attributed to different days.

Column D indicates hourly reading frequency with an unexplained change for twice daily (12) to once daily (24). This subsequently changed back with no known site or instrumentation change.

In conclusion and returning to the start point, whilst Marham superficially looks a reasonably good site and the Met Office has authoritatively displayed incredibly accurate climate averages to it for a sixty year period, what we actually have is

1. A site originally recording to the first decimal place of a Fahrenheit degree down grading readings to a tenth of a celscius degree.
2. Two known re-locations to areas of different climatology none of which are indicated in open records.
3. Extensive missing data, some years long.
4. Unexplained variation in reading frequency.
5. Instrumentation changes from Liquid in Glass thermometers to Platinum Resistance Thermometers.

And yet despite all this we should simply trust the Met Office when they assure us it follows stringent scientific process of world ranking quality……and if you ask for any clarification they refuse to divulge any of their data.

Source: https://tallbloke.wordpress.com/2025/05/10/marham-wmo-03482-a-cautionary-example-of-how-deceptive-met-office-records-can-be/