Oh, and I lucked out on this one.
I'd read all these posts saying how cold British summer can be and people couldn't wear sundresses, etc. So I packed just a few shorts and meant to send the rest with my sea shipment. Total fluke, the box got missed so I had to bring a whole bunch of shorts in my suitcases. Arrived just in time for the first intense heatwave with no air conditioning. Boy was I thankful!
So if you come here, yes it does get chilly in the summer (down to 50 this August) but you WILL want hot weather clothes for the heatwaves. I would have been absolutely miserable if I hadn't had my extra shorts.