On 24 May, 20:51, wrote:
Today's sunshine was 15.20 h here (R&D recorder, correcting for 1-2%
overcounts). The last May day to have recorded 15 h in this area was
over 40 years ago, 31 May 1966 with 15.1 h.

Daylength (sunrise to sunset) 15 h 58 m, so this figure represents
just over 95% of 'astronomical' possible.

The R&D tends to be rather better at low sunshine than the Campbell-
Stokes, which was what was in use in 1966, but even so today's figure
is well in excess of any May total in the 8 years I've been using the
R&D (previous highest 14.41 h on 31 May 2003). The highest daily using
my C/S here 1988-2000 was 14.1 h.

It's also the sunniest day of any since 17 July 2006 (15.22 h) but
that's not that surprising considering the past two summers of course.

Hi, Stephen,

15.7hr here (R&D) today in Copley. Sunniest May day on my record,
representing about 95% possible, similar to yours. Sunrise 03:48GMT,
sunset 20:22GMT on 24th May giving a possible 16hr 34min at Copley
latitude, 54°37' N.
16.1hr July 2006 and 16.0hr June 2005 are the only days to better it,
although most years have a 15hr sunshine day.
Theoretically, a similar day in a month's time would give 16.4hr of a
possible 17hr 17min (03:31GMT to 20:48GMT).
I expect today will be the sunniest of the year.

Best wishes,
Ken
Copley