It is always central England which is subject to the highest temperatures. But, as we were all reminded this week, season is no sure guide to temperature. It snowed once at Lord's cricket ground in June. Icicles were found under the cricket covers during a more recent Nottingham Test match. This might have accounted for the exceptional 18C temperatures recorded in the Welsh borders in January, 1958.
Scientists have a different explanation.
There is very good reason why this should be so.