It’s the last day of what people are now calling ‘meteorological’ autumn, so I thought I would put some code together to display daily Central England Temperature [CET] series for any season as a grid of weekly deciles, along with the corresponding mean temperature and anomaly. I did this so that I could take a closer look at winters in the series since 1772, and rather surprisingly I found no winter has been consistently cold throughout the 13 weekly temperatures deciles (1), although the winter of 1794-95 did come close with 12 out of 13 decile 1 weeks. Another surprise, was that the winter of 1978-79 tied with both 1946-47 and 1962-63 with 10 weeks of decile 1 mean temperatures. One thing that I always seem to be being reminded of is how late the winter of 1946-47 started, and if you look closely the first fours weeks of the winter were indeed average or mild. The code for this has been more than a little awkward to get right, mainly because I’ve added functionality to allow for meteorological seasons and also output the results as quintiles as well as deciles.
It’s seems a long time since the last cold winter in 2009-10, and the weekly deciles since the late 1980’s have been predominantly of the mild 3 variety. The mildest winter that I can see from my results looks to be 1989-90 with 12 weeks of decile 3, followed by 2013-14 with 10 weeks of decile 3, in fact 9 out of the top 10 mildest (astronomical) winters as far as I can see have occurred in the last 30 years if you rank winters by their weekly mean temperature deciles.