Looking at this http://www.met.reading.ac.uk/~brugge/hitemp.jpg it struck me how similar the highest temperatures have been across the UK

On that map, only some Scottish islands have failed to reach 20C, very few places have reached 25C. A warm month so far, but never hot.

For what it's worth, the highest in Penzance so far this month is 23.3C.

Graham
Penzance