Mid-latitude westerly winds bring high pressure weather front that alternate with cold fronts on the winter. This leads to generally drier conditions in the winter months of July and August. In the summer, southeasterly winds bring weather fronts harbouring extensive amounts of moisture. Between October and April more than two thirds of the region's annual rainfall will fall with January and February being the wettest months. Between the months of October–April, the 3pm average for relative humidity in the Lower Hunter is 49%, while it is 43% in the Upper Hunter.