Equatorial Guinea has a tropical climate with distinct wet and dry seasons. From June to August, Río Muni is dry and Bioko wet; from December to February, the reverse occurs. In between there is gradual transition. Rain or mist occurs daily on Annobón, where a cloudless day has never been registered. The temperature at Malabo, Bioko, ranges from 16 °C (61 °F) to 33 °C (91 °F), though on the southern Moka Plateau normal high temperatures are only 21 °C (70 °F). In Río Muni, the average temperature is about 27 °C (81 °F). Annual rainfall varies from 1,930 mm (76 in) at Malabo to 10,920 mm (430 in) at Ureka, Bioko, but Río Muni is somewhat drier
