I have to go with neither. Summer always tends to be way too hot now in the UK, with the humidity being a sticky, horrible heat rather than something you can enjoy.
Winter I always find too cold and not too keen on the dark nights.
I am a summer person 100% because I like the feel of the sunshine, longer days, it just align with my lifestyle. Winter is fine but I don't like the cold, especially in the morning. It is always very worse. Summer just make everything very easy, businesses are booming and life becomes easy too.