BTW, does Penzance ever record maxima below 10C after the end of March?

Not counting the late autumn months, obviously.
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)

Oh yes, on 22 occasions in the last 17 years. The SST off west
Cornwall is typically only 10-11 in April, so does little to take the
edfge off a cold blast.

Graham
Penzance