This month has been noticeable for a lack of any real early summer-like
weather, in contrast to March. On the other hand it hasn't been
noticeably cold either, just uncharacteristically equable, unusual for
a spring month and again in contrast to March.

What's the highest temperature this month so far? Isn't it just under
20c? Can't see it being beaten with a decidedly cool-looking set up for
the next few days; so it looks like this month will have the lowest
April UK maximum for some years; and indeed, we won't beat the March
maximum
When was the last April when 21 C wasn't reached anywhere in the UK?

Nick