The best time to visit Benin is from October to April, particularly January, during the annual Voodoo festival in Ouidah. In the dry season temperatures can rise to 40°C (March-April) in the north, while the harmattan blows dusty air from the desert generally in February. The rainy season corresponds to the months of May-June until September. Slight differences are found between the south, which is characterised by a tropical, humid climate where a few showers are never excluded, and the north, characterised by a Sahelian climate, dry and with a clear differentiation between the two seasons.