Calima is an atmospheric phenomenon when a layer of hot Saharan dust covers the islands. It is particularly prevalent in winter.
Generally, calima in the Canary Islands lasts between 3 and 5 days. The main effect of calima is the worsening of air quality, which causes a kind of dusty fog that makes it difficult to see at long distances. Furthermore, calima leaves streets, cars and houses covered with a thin layer of sand.