The main reasons for the “wet London stereotype” are:
– The UK as a nation is very wet. London is an exception.
– London gets very little sunshine. People will mistake a lot of overcast days with rainy days even if it won’t rain.
– London has a relatively average number of “rainy days” (any form of precipitation) whereas some places “wetter” on this map (such as France) have fewer rainy days but when it does rain – it rains a lot more.
– It very rarely snows in London, so almost all precipitation measured is rain, rather than in Zurich or Vienna where they get a lot of snow instead.
– Find cities with a similar climate