Cape Verde's climate is milder than that of the African mainland because the surrounding sea moderates temperatures on the islands. Average daily high temperatures range from 23 °C (73 °F) in January to 29 °C (84.2 °F) in September. Cape Verde is part of the Sahelian arid belt, with nothing like the rainfall levels of nearby West Africa. It does rain irregularly between August and October, with frequent brief-but-heavy downpours. A desert is usually defined as terrain which receives less than 250 mm (9.8 in) of annual rainfall. Cape Verde's total (265 mm/10.4 in) is slightly above this criterion, which makes the area climate semi-desert.
The islands, covering a combined area of slightly over 4,033 square kilometres (1,557 sq mi), are of volcanic origin and while three of them (Sal, Boa Vista and Maio) are fairly flat, sandy and dry, the remaining ones are generally rockier and have more vegetation. However, because of the infrequent occurrence of rainfall the overall landscape is not particularly green. The archipelago can be divided into four broad ecological zones: arid, semiarid, subhumid and humid, according to altitude and average annual rainfall ranging from 200 mm in the arid areas of the coast to more than 1000 mm in the humid mountain. Mostly rainfall precipitation is due to condensation of the ocean mist.
In some islands, as Santiago, the wetter climate of the interior and the eastern coast contrasts with the dryer one in the south/southwest coast. Praia, located on the southeast coast, is the largest city of the island, and also the largest city and capital of the country.
Because of their proximity to the Sahara, most of the Cape Verde islands are dry, but on islands with high mountains and farther away from the coast, by orography, the humidity is much higher, providing a rainforest habitat, although much affected by the human presence. Northeastern slopes of high mountains often receive a lot of rain while
