Lanzhou is warmest in July, averaging 28° by day and 14° at night. The wettest month is August with 93 mm, and the year brings about 490 mm in total.
Month by month
| Month | High | Low | Rain | Daylight | Good for |
|---|---|---|---|---|---|
| January | 1° | -11° | 3 mm | 9.8 h | Cool |
| February | 5° | -8° | 11 mm | 10.6 h | Cool |
| March | 12° | -3° | 19 mm | 11.7 h | Cool |
| April | 16° | 2° | 42 mm | 12.9 h | Mild |
| May | 22° | 6° | 50 mm | 13.9 h | Sightseeing |
| June | 25° | 12° | 63 mm | 14.4 h | Beach weather |
| July | 28° | 14° | 78 mm | 14.2 h | Beach weather |
| August | 27° | 13° | 93 mm | 13.4 h | Beach weather |
| September | 22° | 8° | 75 mm | 12.2 h | Sightseeing |
| October | 15° | 2° | 47 mm | 11.1 h | Mild |
| November | 9° | -4° | 6 mm | 10.0 h | Cool |
| December | 1° | -10° | 3 mm | 9.6 h | Cool |
High and low are average daily maximum and minimum, rain is typical monthly total, daylight is the hours between sunrise and sunset mid-month. Climate normals from NASA POWER — averages, not promises.
When to go
Beach weather: June, July and August — highs around 27°, nights no colder than 12°, and at most 93 mm of rain in a month.
Walking the city: May and September — highs of 22–22° and no more than 75 mm of rain a month.