What About August 2023?

I take a quick look at the Central England Temperature Record (HadCET) to see how August fared in the new era of global boiling

August has come and gone and, like July before it, we found ourselves popping the central heating on now and then and resorting to sweaters, warming soups and Norwegian wool socks. We would have put a couple of logs on the wood fire but this isn’t a good idea when honey bees are nesting in your chimney. The boiler it is, then.

With weather conditions pretty similar to those in July I had been waiting for yet another announcement by talking heads that August 2023 had broken all temperature records since time began. This never came, so I presume they’re trying to avoid eye contact.

Two can play at this game so this fine September morning, with tweety birds singing outside my office window, I downloaded the venerable and most trustworthy Central England Temperature Record data from here, then whipped my crayons out:

Herewith a scatterplot of all mean daily August temperatures since time began in 1772. The thin black line is one of those linear trend thingummies that everybody plots, and I shall reveal that the positive slope is statistically sound, offering a warming rate estimate of +0.32°C per century (p=0.001). If we slap a 95% confidence interval around this we get a range that lies somewhere between +0.13°C and +0.52°C per century. Thus, we observe English Augusts are getting warmer but at a very modest rate.

All this is with our linear hat on, of course. We have also got a nice bobble hat called locally estimated scatterplot smoothing (LOESS), and this gives that wobbly green snake that reveals planetary life is more complex than ‘things getting warmer’. That green snake reveals alternating patterns of warming, cooling, and not doing very much. The most recent spate of August warming across the nation of England ran from 1960 to 2000 or thereabouts and now seems to be resting on its perch.

Speaking of perches we might enquire as to where August 2023 falls into the scheme of mean daily August temps, and I shall reveal that, at 16.37°C, it managed 71^st position in the grand list of 252 Augusts since 1772. Hence the need for soup, socks and sausage sizzlers. The thermally curious may wish to note gold went to 1995 (19.14°C), silver went to 1997 (18.95°C) and bronze went to 2022 (18.71°C), all being a jolly good showing for the modern era.

With August in the bag we may now calculate the mean daily summer temperature (June, July, and August) and crayon a similar chart:

And there it is! Linear regression now produces a rather weedy warming trend of +0.19°C per century (95%CI[0.05,0.34]; p=0.008), and we discover that summer 2023 landed-up in 24^th place with an overall daily mean of 16.50°C. The gold went to 1976 (17.69°C), silver went to 1826 (17.61°C) and bronze went to 2018 (17.36°C).

Summer is supposed to be the hottest time of year but when taken together the months of June 2023, July 2023 and August 2023 offer a spectacularly mediocre performance that is being described in pejorative terms such as ‘climate crisis’, ‘climate emergency’ and ‘global boiling’.

Kettle On!