Weather:
The UK has lots of it, and it's the eternal topic of conversation, so start practicing comments like:
Not much of a summer is it?
It's so wet I've developed webbed feet.
You'll find that we don't take well to extremes of weather either - so more than two days in a row of >25C/75F is a heatwave, any one day at/below 0C is "Britain freezes in arctic blast", more than 0.5 in of snow and the entire road and rail system grinds to a halt and more than 2 inches of rain in two days and we have floods.
Apart from that it's fine.