Now that summer has finally drawn to a close I thought I would look at how the astronomical summer finished in the Central England Temperature [CET] series. The mean CET of the astronomical summer was slightly higher than that of the meteorological one (1st June – 31 August) at 16.70°C, or +1.36°C above the 1961-1990 long-term average, which made it the warmest since 2006, and the 19th warmest in the daily series that started in 1772. A couple of caveats to all this are (1) the values are based on September provisional values (2) I use fixed dates in my climate statistics for the seasons, so summer starts on the 21st of June and ends on the 20th of September, and yes I do know that the date and time of the equinoxes varies.
Ranked on night-time minima the summer of 2016 was joint 3rd warmest. So it looks like the higher number of warm nights and the high mean minimum CET bolstered up the final mean CET of the summer. Not all years are like 2016 where the mean maximum anomaly is matched by the mean minimum anomaly. If you look at the above graph the blue diamonds indicate where four new highest minimum CET records were broken during the summer.
The table below shows a count of when maximum daily CET was equal to or exceeded 25, 26.7 or 28°C. There were only 8 days when the maximum daily CET was 25°C or higher during the summer of 2016. Interestingly, the summer of 2013 had double that number of days but a slightly lower mean (16.24°C), but that again can be explained by the mean minimum in 2016 which was +0.93°C higher than in 2013.