Source: The Library Of Congress Country Studies
The climate is generally warm and humid and is, overall, transitional from equatorial to tropical. Seasons are more clearly distinguishable by rainfall and wind direction than by temperature. Continental and maritime air masses, following the apparent movement of the sun from north to south, determine the cycle of the seasons that is associated with heat and cold farther from the equator.
During the first half of the year, the warm maritime air mass pushes northward across Côte d'Ivoire in response to the movement of the sun. Ahead of it, a low pressure belt, or intertropical front, brings warm air, rain, and prevailing winds from the southwest. As the solar cycle reverses at midyear, the continental air mass moves southward over the nation, permitting the dry northeast harmattan to dominate. Surface winds are gentle, seldom exceeding fifteen to twenty kilometers per hour.
Two climatic zones are created by the alternating wind patterns. In the north, tropical conditions delineate two major seasons. Heavy rains fall between June and October, averaging 110 centimeters annually. Along the coast, equatorial conditions prevail. Some rain falls in most months, with an average of 200 centimeters annually, but four seasons are generally distinguishable. Heavy rains fall between May and July in most years, and shorter rains during August and September. The minor dry season still brings sparse rainfall during October and November, followed by the major dry season from December to April.
Temperatures and humidity generally follow the same pattern, with average temperatures between 25° C and 30° C and ranges from 10° C to 40° C. Temperatures are higher in the south but may exceed 30° C even in the far north. Annual and daily ranges of both temperature and humidity are small along the coast but increase progressively toward the north. The average relative humidity is 85 percent in the south and 71 percent in the north.
Data as of 1988