Pakistan's climate is dry and hot near the coast, becoming progressively cooler toward the northeastern uplands. The winter season is generally cold and dry. The hot season begins in March, and by the end of June the temperature may reach 49°c (120°f). Between June and September, the monsoon provides an average rainfall of about 38 cm (15 in) in the river basins and up to about 150 cm (60 in) in the northern areas. Rainfall can vary radically from year to year, and successive patterns of flooding and drought are not uncommon.