Lanzhou has a typical temperate, semi-arid continental monsoon climate. It has abundant sunshine and dry weather. The annual precipitation is 328 millimeters (13 inches), which is concentrated from May to September. So an umbrella and raincoat should be packed in your bag if you plan to visit Lanzhou at that time. Since it is very dry in Lanzhou, it is suggested to drink lots of water and wear sum protection. The best to visit Lanzhou is from May to October when the temperature is most suitable.
Spring is from March till May. There are dust storms due to the rapid increase of temperatures, but only occasionally. The warm sunshine and gentle breeze make spring a good time for traveling and outdoor activities.
Summer is from June to August, usually scorching with sizzling temperatures at noon. There are occasional downpours. Umbrella, sunglasses and sun screen are recommended. Wear any summer clothes, such as T-shirts, shorts and skirts.
Weather is changeable with big temperature difference during day and night. The first snow comes in mid-October or early-November, and temperatures fall lower after the first snow. Average temperatures are 9 to 21 °C (48-69 °F) in September, -6 to 12 °C (31-54 °F) in October and -11 to -6 °C (12-31 °F) in November.
Winter is from December to February of the next year. Winter is cold with frosty nights and strong winds, although the sea does not freeze. Temperature often falls below 0 °C (32 °F). January is the coldest month of the year. The average low and high temperature is respectively at -1 °C (30 °F) and 5 °C (41 °F) in December, -4 °C (25 °F) and 2 °C (36 °F) in January, and -3 °C (27 °F) and 3 °C (38 °F) in February. Prepare warm winter clothes such as down jackets and thick sweaters for winter.