The web says this:
Manchester has a relatively damp climate and a reputation as a rainy city. The average annual rainfall is 809 mm, (902 mm from some sources)[15]meaning that its reputation is relatively undeserved.[16] For example, this total is less than that of Plymouth, Cardiff or Glasgow. In international terms, Manchester receives substantially less rain than New York City, which receives 1200 mm of rain in an average year, and its average annual rainfall total is comparable with that of Rome. The precipitation is regularly light and prolonged, however, so a small volume of rain may take an hour to fall in Manchester, compared to several minutes of heavy rain experienced in Rome. Manchester also has a relatively high humidity level, which lent itself to the optimised and breakage-free textile manufacturing which took place in the city. Snowfall is rare in the city itself, being low-lying, towards the west coast and an urban landscape.
Not that I'm bored or anything...