The climate is tropically hot and humid in the lower western and central regions, with frequent heavy rains from October or November through May south of the equator and from April to June and September to October in the north, while along the equator itself there is only one season. In the cuvette, temperatures average 24° C (75° F ), with high humidity and almost no seasonal variation. Annual rainfall is between 130 cm and 200 cm (51–79 in). In the northern and southern plateaus there are wet and dry seasons, with temperatures slightly cooler in the latter and annual rainfall of 100–160 cm (39–63 in). The eastern highlands have temperatures averaging 18° C (64° F ) and 24° C (75° F ), depending on the season. Rainfall averages 120–180 cm (47–71 in).