What's been noticeable about the current showery spell, all 10 days or
so of it, is the lack of the traditional overnight clearance and clear
mornings. The shower activity has followed the traditional afternoon
and early evening peak, with fairly reliable dry conditions after 7pm,
but overnight the skies have largely been overcast by non-rain-
producing cumulus. This appears to have not been just a local coastal
effect - the cloud has been continuous to the north (observed from
Southampton) around 9am each day.
One or two evenings were clear but very few mornings - the only clear
skies at 9am being when the warm airmass intruded on Tuesday.

I guess the night time temps have not been cool enough (most evenings
have been rather muggy) to drop below the temperature required for
cloud generation?

Nick