Once again the Met Office jumped the gun and declared, with several days still to go, that the UK will have its “hottest June on record, beating the previous record set in 1940, as well as June 1976 (part of the well-known summer of 1976), which is currently the second warmest June on record.”
There’s renewed reporting of the record today with the Met Office expected to confirm it (though I can’t yet find an actual press release from them).
As I’ve lamented before, saying “this is the UK’s hottest June on record” is an example of Premier League syndrome. Just as it seems all English football records now begin in 1993, over a century after the modern game began, so older weather records are ignored, even when data exists.
In this case, the Met Office has referred only to UK-wide data they’ve been collecting since 1884.
If we look a little further back, at the Central England Temperature (CET) record, also published by the Met Office and which correlates quite well with UK-wide records, we see that June 2023 is far from the hottest:
Here we see that 3 of the 4 hottest Junes since 1884 in the CET record – 1940, 1976 and 2023 – are the 3 hottest for the UK as a whole, as reported by the Met Office, although the order is slightly different, with 2023 tying 1976 at 17.0C and 1940 only equal 3rd hottest, equal with 1970 at 16.4C.
However, if we go back further we see that June was a little hotter in both 1822 and 1826, but significantly hotter in 1846, at 18.2C and in 1676 at 18C. The figure for 1846 is sufficiently recent to be fairly reliable, I would have thought (indeed, weather maps exist for 1846).
The way I look at this is that, in overstating the heat this year, the Met Office is also understating the risk. As I suggested last time, the weather has been hot, but not extreme this year, yet records have nevertheless been broken because every year is hotter due to global warming.
Have another look at the graph above. The black line shows the 21 year running mean centred on each year. This mean is currently approaching 15C, so June 2023 was “only” 2C warmer than the average June these days.
By comparison, 1976 was nearly 3C hotter than the average then, and 1846 and 1676 were about 3.5C hotter than the averages for the time!
A really freakishly hot June right now would be expected to have a mean CET of over 18C – possibly well over – not the 17C we have just experienced.
And, of course, the average June continues to become hotter.