We benefit from the Gulf Stream which keeps us unusually warm.
I'be known this from a young age when my Dad's proposal to beach holiday "abroad" was aa week camping on Arran.
The sea will be like a warm bath he said, because of the gulf stream. Nearly 50 years later I have just about warmed up again.

looking back funds were tight, and his argument that Scotland was a different country, and we had to use a ferry to get there so it counted as "abroad" was quite neat.
But yes the gulf stream and being surrounded by sea does act as the UK's hot water bottle.