In uk.sci.weather on Wed, 17 Sep 2003 at 01:24:01, Philip Eden wrote :

Paul Hyett writes:

ISTM this year must have had the longest period between first & last
80F+ readings on record - the first in mid-Apr, and still ongoing.

1959 might be in contention. The first one was probably some time in
May, the last one in early October, IIRC.
--
Well remembered, John. 10 May to 3 Oct, but that's already shorter
than this year. 1949 and 1921 don't pass muster either. Nor does
1893. The longest I could find was 1908 (4 May to 4 Oct incl.)
which we have equalled today (16 Apr to 16 Sept incl.) and
should beat tomorrow.

Given the repeated return of warm weather this summer, another 80F+
beyond this current spell wouldn't surprise me too much. The LRF set-up
still seems favourable to the possibility.
--
Paul Hyett, Cheltenham, England