Generally the climate is wet and tropical. Summer is the principal rainy season although there is no specific dry season. Temperatures range from very hot at sea level to relatively cold at higher elevations but vary little with the season. At Bogotá, for example, the average annual temperature is 15°C, and the difference between the average of the coldest and the warmest months is less than 1°C. More significant, however, is the daily variation in temperature, from 5°C at night to 17°C during the day.The climate is very warm and tropical on the coast and in the north, with a rainy season from May to November. This varies according to altitude. It is cooler in the upland areas and cold in the mountains.The average temperature in Colombia is 13.0 °C (55 °F).The highest monthly average high temperature is 21 °C (70 °F) in January to March.The lowest monthly average low temperature is 4 °C (39 °F) in January.The wettest weather is in October when an average of 131 mm (5.2 in) of rainfall (precipitation) occurrs across 17 days.The average annual relative humidity is 79.0% and average monthly relative humidity ranges from 76% in February to 83% in November.There are an average of 1710 hours of sunlight per year with an average of 4.7 hours of sunlight per day.The best time for the country as a whole is December-March — it rains the least then.