Adrian D. Shaw wrote:
Felly sgrifennodd :
This could be evaluated in a measurement of "extremity" of a calendar
year: the mean maximum of the hottest month (probably July this year)
and the mean maximum of the coldest month (February this year).

Why not just the mean temperature of these months?

For comparison, he

Mean max: July 22.9 - Feb 5.9 = 17.0

Mean: July 17.6 - Feb 2.9 = 14.7

and Copley is slightly more because of the greater continental
influence on the eastern side, although last winter was slightly milder
than average. Using the mean always drags us down as nights are often
cool here.
Mean max: July 24.3 - Jan 5.1 = 19.2
Mean: July 17.7 - March 2.5 = 15.2

However in 1983 at Low Etherley 155metres asl (nearby Met O station
that I ran) when decent winters still happened around here.
Mean max: July 22.4 - Feb 3.3 = 19.1
Mean: July 17.3 - Feb 0.5 = 16.8

there are several others that are close and 1947 in Durham was
Mean max: August 23.0 - Feb 0.6 = 22.4
Mean: August 17.2 - Feb -1.1 = 18.3

I expect the South East will have greater extremes.

Ken
Copley 253metres asl, nr Barnard Castle, County Durham
http://copley.mysite.orange.co.uk