May in Lanzhou averages a daily high of 21.9°C with nights around 6.3°C. Expect roughly 10 wet days totalling 52.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Lanzhou is April–September.
Based on YU ZHONG, CH (35km), 1995–2024. 14 years of May data.