Kunming's reputation as the "spring city" is well earned. Sitting at 1,890 metres on the Yunnan plateau, the city avoids both the sub-tropical summer heat of lowland China and the bitter winters of the north — daytime temperatures sit between 15 and 25°C year round, and the sun is almost always shining.
The driest, brightest months are October to April, the best time for sightseeing. May, June, July, and August bring afternoon thunderstorms that can be heavy but rarely last all day. December and January are the coolest, with nights dropping near freezing — Kunming buildings are poorly heated and you will want layers. The Spring Festival period (late January / February) brings huge domestic crowds to the major sights and the migrant gulls on Cuihu are at their peak.