Yunnan has a diverse and unique climate, owing to the low latitudes but high altitude. The climatic zones in Yunnan range from tropical to frigid. In some areas of Yunnan, winter is long, but in some areas, summer is prevalent all year round, and when it rains, the temperature drops drastically.

In Yunnan, there is little difference in temperature on monthly basis throughout the year, but much difference in temperature during the day. In summer, the rainy season (usually from May to September), even in the hottest days, the average temperature is no more than 22 degrees centigrade. In winter, the average temperature in the coldest month is above 6 degrees centigrade.

Yunnan gets plenty of rainfall which distributes unevenly in terms of season and area. In summer, some areas are often hit by floods. While, in winter and spring, drought is common. Some parts of Yunnan receive an annual rainfall of above 2000 millimeters, but some areas only get less than 900 millimeters.
The vertical change in Yunnan's climate is remarkable, and the temperature varies considerably with the altitude. There is a popular local saying which goes "there are four seasons on one mountain and the weather is different 10 miles away".

In some areas where the elevation is between 1500 and 2000 meters above sea level, the weather is pleasant during most of the time, but when it rains, it gets cold. Most parts of Yunnan are about 2000 meters above sea level where the climate is pleasant throughout the year. Therefore, Yunnan is an ideal travel destination all year round.