We simply do not allow for the weather in this country.
I believe this is because, unlike just about every other country, we do not have a climate ~ we have weather.
Finns, Danes, even Canadians have two basic wardrobes. One for the warm seasons and one for the cold. Even in Germany and Holland people dress according to the season ~ we do not. The British expect to be able to walk around, no matter what time of year, with flimsy clothing and an umbrella. Wear anything else and you are seen as a loony. The same applies to driving, trains, airports etc. All gubbed because we don't "expect the weather to change" because, unlike the others, we don't have a recognised seasonal climate.
Example:
Daughter will NOT wear an anorak to school (White, fur trimmed, 15 tog "duvet" style filling) because "It makes me look fat" so today she goes off in a pair of normal school trousers, "ballet" pumps and a sweatshirt (and the latter only because it is compulsory school uniform) ~ She even pushes up the sleeves of her sweatshirt as a protest at having to wear it. Goose bumps like you wouldn't believe but will she put a coat on ~ NO!