This is a good example of just how patronising the Met Office can be when they are wrong. Yesterday on Twitter they announced that there had been a 21.7°C diurnal range in temperature between a minimum of -6.0°C at Topcliffe in Yorkshire, and a maximum of the 15.7°C at Trawsgoed in west Wales. A couple of people pointed out that a diurnal range in temperature was usually measured at the same location.
Of course that wasn’t good enough for the Press Media team down in Exeter so to get the last word they put out the explainer: ‘What is a diurnal temperature range?‘. My advice to them would be to accept when the are wrong more gracefully and admit that Jasper and Official Weather UK were right. It would have been no more useful of them Tweeting that yesterday there had been an 85.8°C diurnal range between the -41.0°C at Resolute (#71018) in the north of Canada and the 44.8°C at Diffa (#61085) in Niger. Why? Because the extremes are not from the same place.
The mere fact that they’ve written an explainer concerning diurnal range indicates to me this is not the first time they’ve been challenged on this subject. All that was missing from the Tweet was the issuing of a reprimand telling them to stay behind after school and write a hundred lines on the blackboard “The Met Office are never wrong and diurnal range means what ever we want it to mean“.
Often imitated but never equalled
Here is a chart of the diurnal range at each station yesterday across the UK. I’m afraid that because the Met Office like to keep climate data to themselves they don’t publish the 21-09 minimum or the 09-21 maximum temperatures from all of our climate stations, so I have to make do with downloading SYNOP data from Spain and using the 18-06 minimum and 06-18 maximum from the SYNOP reports. As you can see the largest diurnal range across the UK yesterday – which strictly should be measured from midnight to midnight – was 19.2°C at Redesdale Camp and not a combination of Topcliffe and Trawsgoed extremes. Of course 21.7°C made a better headline than 19.2°C did and that wouldn’t do.