Cumulus humilis is a cumuliform cloud with little vertical extent that is commonly referred to as "fair weather cumulus". It is generally classified as a low cloud, but in hot countries and over mountainous terrain these clouds occur at up to 6,000 m (20,000 ft) altitude. Elsewhere they are typically found lower levels (500–3000 m (1,500–10,000 ft)). Cumulus humilis may be accompanied by other cloud types. When they appear in a clear sky (see picture), they are an indicator of pleasant weather for the next several hours.