Located inland, Lanzhou has a typical temperate, semi-arid continental monsoon climate. It is dry with plenty of sunshine. Winter is long and chilly with an average temperature of -7.3C(18.9F) while spring is ephemeral with changeable weather. In winter, a warm coat, scarf, gloves, hat, and boots are needed. Summer is short but not too hot with an average temperature of 22.4C (72.3F). A warm coat is a necessity on your trip to Lanzhou since the temperature can drop considerably in the evening. Autumn sees a rapid decrease in temperature. Though historical records show that in some extreme cases the temperature can be as low as -23.1C (-9.6F) and can rise to as high as 39.1C (102.4F), Lanzhou enjoys a favorable climate. The annual precipitation is 328 mm (12.91 inches), which is concentrated during the summer. So an umbrella and raincoat should be packed in your bag if you plan to visit Lanzhou at that time. The best season is usually from May to October when the temperature is most suitable. Other things to carry with you are a bottle of water, and sun protection, especially a lip balm. If local folk customs like festivals appeal to you, winter is also a good tourist season.

Visitors interested in the local festivals and who do not mind the climate, go to Lanzhou in January, February, July or August for the following events.

Labrang Monastery in Xiahe County holds seven religious festivals annually, with the ones on the first moon and seventh moon being the most famous. The highlight of the 1st moon gathering is the Buddha Unfolding on the 13th day and the Yak Butter Sculpture exhibition on the 15th day. Tourists are welcome at these festivals.

Hua'er Folk Music Festival at Lanhua Mountain, Linxia County is held from the 1st to 6th of the 6th moon every year. Hua'er is a type of folk music. At the Hua'er Festival, Hua'er singers come from the neighboring areas and bring their talent into full play, singing impromptu song after song. This festival is of such importance that all the counties offer tour buses to the Hua'er performances.