Colombia's climatic variations are determined by altitude, and seasons are periods of lesser or greater rainfall, with little or no temperature change. The country may be divided vertically into four regions. The hot country, ortierra caliente, is the tropical zone, reaching from sea level to roughly 1,100 m (3,500 ft), where the mean annual temperature is 24°c to 27°c (75–81°f); at sea level, temperatures have a mean maximum of 38°c (100°f) and a minimum of 18°c (64°f). Between 1,100 m (3,500 ft) and 2,000 m (6,500 ft) is the temperate zone, ortierra templada, where the average year-round temperature is about 18°c (64°f). Between 2,000 m (6,500 ft) and 3,000 m (10,000 ft) is the cold country, ortierra fría, with temperatures averaging a little over 13°c (55°f). Above the 3,000 m (10,000 ft) level the temperature varies from 13°c to -17°c (55°f to 1°f), according to altitude. The annual mean temperature at the capital, Bogotá (altitude 2,598 m/8,525 ft), is 14°c (57°f).