BALA WMO03409 – A “confusion of names” and why that matters

52.90757 -3.58423 Met Office CIMO Assessed Class 4 Installation and operational dates open to question.

Following a short sabbatical I am now resuming the Surface Stations Project. Initially completing the review of all currently operational weather stations and some key former sites, I then intend to move onto further analysis of data from verifiable well located sites as started with my review of Wye. I also intend to clarify and further explore specific issues regarding station siting and data reliability starting with non-apparent relocations. Bala is a notable example of confusions over names and locations.

The site now shown publicly as just “Bala” lies about a kilometre to the south east of the town centre and 800 metres to the north of Llyn Tegid (Bala Lake) in an artificially developed area of sluices dating from the 1840s. This area was most recently further developed in the latter 1950s to control water levels in the lake and provide regulation to a complex drainage, water supply and transport system down stream.

When Tim Channon first reviewed the site, he acknowledged difficulty in classifying exactly how this type of site should be judged and did not offer a final opinion. The quite unnatural nature of the man-made area should mark the site down though obviously such natural lakes as Llyn Tegid are typical of the area. The Met Office’s subsequent judgment of Class 4 seems reasonable with the caveat that the site is alongside a commercial roadway. Traffic will be infrequent to the sluices from the apparent works hard-standing area to the west but modern rapid responding electronic PRT’s will pick up even very brief transient effects from motorised vehicles potentially elevating daily maxima.

Given that the Met Office acknowledges the site is defined as “Class 4 (additional estimated uncertainty added by siting up to 2 °C)” it should not be appropriate to base climate history to the second decimal place of a degree on such unreliable data – but they do.

When I encounter these climate averages stations I investigate their “provenance” quite deeply. Experience has told me that sites are very often significantly relocated over time without any immediate evidence being shown such as at Cambridge NIAB , Braemar and many others. It is also the case that many are either long closed (e.g. Lephinmore deceased 60 years ago) or have significant and very important gaps in their history such as Ross-on-Wye. This is what the Centre for Environmental Data and Analysis official record shows for the site named “Bala”.

This looks very straightforward ,”BALA” has a station start date of 1939 and is “Current”. However, the temperature data has only been digitally archived from 1970. This always raises my suspicions – the above climate average period from 1961 to 1990 may be missing almost a decade….or even possibly more.

At this point I delved into the murky world of manual copied records and immediately found “BALA” (filed under Merionethshire) but not quite as I expected.

The coordinates given (55.55 – 3.37) did not match the current location but were too imprecise to pinpoint exactly where this “Bala” station actually was. This is where applied logic and a bit of triangulation came in handy. These old manual records also noted “Objects Used for Estimates of Visibility”, two of which were The White Lion Hotel at 55 yards (50 metres) and Railway Station at 1100 yards ( 1000 metres). Working from a website allowing the drawing of an area enclosed circle that I regularly use, I found the intersection points where the weather station should be located.

Putting this point into Google street view I discovered that one of the two was looking straight at the Plas Coch Hotel. Ironically I could have saved myself all this trouble as the Met Office form actually does state the viewpoint as being from “Plas Coch entrance” The comforting point was that at least all the effort confirmed my system worked. This original site was 1 kilometre from the current one.

This High Street location was not unusual for the period such as I noted at Wick and being alongside the Post Office allowed for rapid telegraphic transmission of reports. Bala high street was also very different with the few cars there were actually parking between the trees and the pavement – try to imagine that now!

At this point I felt I had confirmed a site relocation……or had I? I tried further research into the Met Office library files of historic archive holdings just to confirm what I thought I knew only to be even further surprised.

The important note here was – “NOT Bala Sluices 5255, 0336W – different site” (and also a long missing period that was clearly incorrect as I had viewed manual copies, one such shown above) – So what this is actually confirming is that there were two separate sites, the original called “BALA” and a separate site known as “BALA Sluices”. Further investigation into this “Sluices” site revealed that is was indeed close to (but NOT at) the current location from 1939 to 1949 whereupon readings stopped whilst the redevelopment works took place. The slightly relocated site eventually reopened in 1970.

None of this is openly apparent from the digital archive and there is, in fact, no record of the original Plas Coch hotel site shown despite the newer “Sluices” site adopting its predecessor’s name. But what was that note again? “NOT Bala Sluices”. So where in all of this do those early years figures of the “Climate Averages” actually come from?

This detail is to help explain why Met Office office representations of “Climate Averages” and thus the alarmist claims stemming from them are not examples of accurate data presentation. None of the data provided by the Met Office is demonstrably accurate nor of reliable provenance. Indeed I would argue the Met Office themselves are not even sure where such data actually comes from. Their own archives show no primary data, i.e. actual temperature readings, between 1956 and 1970 from either site and the current site has none from 1949 to 1970. Where are all the interim periods (i.e the 1950 to 1980 30 year averages available but not online) actually coming from – there are no other nearby weather stations.

This reinforces the prerequisites I made regarding Wye, that any sites used for long term climate record reconstructions should have good provenance of CIMO Class 1 and 2, not be relocated nor have any significant site degradation for any reason, and instrument type changes must be avoided. I will expand on these requirements and how I monitor them for quality control over future posts.

Bala is a classic example of how the Met Office are not producing good quality representation and why the majority of their “findings” are not credible. This is another “site” to be disregarded.

Source: https://tallbloke.wordpress.com/2026/04/01/bala-wmo03409-a-confusion-of-names-and-why-that-matters/