The climate is tropical. The coastal areas are hot and humid with an average day temperature of 30 degrees centigrade. The central plateau is dry and arid with hot days and cool nights. In the northwest highlands around Arusha and Ngorongoro, the climate is temperate and cooler between June and September. The long rains are from March to May and the short rains fall between October and December. The hottest months are between October and February