Tetford DCNN2466 – Another typical example of Met Office dross.

53.25330 -0.00945 Met Office CIMO Assessed Class 4 Temperature records from 1/2/1999

Tetford is a small village about 10.5 km (6.5 miles) northeast of Horncastle in the Lincolnshire Wolds Area of Outstanding Natural Beauty. It is also just 20 km (12.5 miles) northeast from the site of the UK highest recorded temperature of 40.3°C set on 19/7/2022 at RAF Coningsby though in a significantly different topography at 53 metres (175 feet) higher elevation.

A point often raised with me is whether or not I am being overly “picky” – does location matter as much as I suggest? I compared Brooms Barn with Felsham to illustrate this very point. With raw data from two neighbouring sites realistically at opposite ends of the quality standard, discrepancies of +6°C/-4 °C in recorded maximums were demonstrated. This conforms almost exactly to the range variance between Class1/2 and Class 5 sites {N.B. this is a +/- error margin.}

“2.6 Class 5 (additional estimated uncertainty added by siting up to 5 °C)“

Further in that comparison, even greater discrepancies in the error margin were demonstrated in the minimum temperatures recorded when Time Of Observations Bias from traditional manual observation protocols were added. The reality is that the errors are frequently not just a few tenths of a degree but rather actually into double digit errors on surprisingly regular occasions.

This entire concept of gross inaccuracy of the recorded readings being genuinely representative of both location AND time is difficult for the general public to comprehend. There is a general assumption that their national meteorological agency would at least be accurate in recording historic data even if not forecasts. The reality is that they are demonstrably, at times, grossly inaccurate on a known and ongoing basis.

Tetford weather station may superficially appear as an “okay” site, however, in reality it represents a classic example of many of the failings that significantly distort the national historic temperature record.

The headline image highlights several factors. Clearly this site is on a significant slope with the brown foliage seen at the bottom being the top of the road side hedging that the camera roof mounted on the car can just see over. The station height of 59 metres (194 feet) runs down to 53 metres at the nearby River Lynn creating a slope down which cold air drains down on cold calm nights. The roadside hedging will block air down-flow and result in cold air pooling up to and around the screen. Tetford is a manually observed site so there is frequent liklihood of over recording these cold instances into following days.

The 30 metre circled area (top orients north) indicates the extensive wind shielding this area will encounter from every compass point. The modern large barns to the west are over 7 metres high to the ridge and in addition to blocking/reducing wind speed have an extensive area of hardstanding artificially over warming in sunny conditions.

The trees to the south are also very high as indicated by this midday image (shading running north) from early October 2019. A casual glance of a “rural” site in reality reveals the extensive artificial influences of the mechanised agricultural industry. The prevailing winds being from the south west are likely modified to a very gently but artificially warmer breeze.

This Telford site will inevitably suffer from general siting inaccuracy from being unrepresentative of the natural environment, unnatural cold air drainage pools and Aitken effects from higher incidence of low wind speeds. The instrumentation was changed from LIGT to PRT at the end of 2017 with the latter likely to react to the transient heat spikes from the extensive vehicle movements visible by their tracks as shown below.

Finally the time of observation bias is readily visible even from just scanning comparative dates with Coningsby. Though different in terrain from the dead flat low level airfield site, Tetford is so close that there should not be regular significant differences. However, simply referring to instances of cold temperatures one day with much warmer ones the next at Coningsby, regularly reveals two consecutive low minimum day’s readings at Tetford that did not occur.

In summary Tetford is yet another exclusion from a historic temperature record reconstruction due to unreliable data.

Source: https://tallbloke.wordpress.com/2026/01/20/tetford-dcnn2466-another-typical-example-of-met-office-dross/