by P. Homewood, Jan 4, 2023 in NotaLotofPeople KnowThat

https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_max2023.html

I want to focus on the end of year CET graph, which gives the lie to the extreme temperature myth often bandied around.

The graph plots daily max CET temperatures, against the background of the percentiles of the 1961-90 climatology. The Met Office should of course be using 1991-2020 as the baseline, so the climatology should be shifted upwards by a half a degree or so. But we’ll leave that aside.

We can legitimately regard anything between the 5% and 95% bands as being “weather”. Only days outside this might be regarded as “extreme”. (I would actually argue anything outside 1% and 99%).

We see that apart from a handful of days, every day was within that “normal weather” band.

In a year there will be 36 days outside of that band on average. The Met Office do not supply the data for these percentiles to enable the number of days to be calculated, but this year it does not look to be excessive in terms of that average.

Moreover, although there were a few days in September which set record highs for that particularly day, none were records for the month as a whole. The highest temperature last September was 28.9C, but the record for September stands at 31.5C in 1906:

…

Of course most of the year had temperatures above the average. But we have a wide range of weather in Britain. We can have mild, wet winters, and cold, snowy ones; we can have cool, wet summers and sunny hot ones. But these are weather events, not climate, and they are dependent on weather patterns, the jet stream and so on.

A predominance of warmer weather is not climate change.