Raining

Cotton mostly, not wool, hence Manchester's old nickname of Cottonopolis. Wool tended to go east to Yorkshire, where it was worked in Halifax, Bradford and Leeds. Yorkshire has a lot of sheep, and used to have even more. But otherwise yes, you are correct. The damp climate of North-West England was an important part of it becoming dominant in the 19th century cloth trade, because it made the fibres easier to work with. Cotton fibres are a serious fire risk if they are dry.