Elongated in shape, Gansu lies at the confluence of the three different landforms in Northwest China. It measures 1,655 kilometers from east to west and has a varied climate because of its unique geographical features.The southeastern part is largely in the subtropical humid area. But the province becomes sub-arid and finally arid as we go northwestwards. The south-eastern part comprises the Southern Gansu Highlands and part of the Loess Plateau. It is humid and belongs to the eastern monsoon zone. The northwestern part, which embraces the Hexi Corridor, the Beishan Mountains, and the Alashan Plateau, is arid. The southwestern part, which encompasses the Qilian Mountains and the grass-tends in Gannan, is humid but cold. Precipitation changes with the terrain. The annual precipitation in southeastern Gansu is 800 millimeters. However, it decreases gradually to only 30 milli-meters from southeast to northwest.The annual temperature varies between 0 ℃ and 15 ℃.
Average Monthly Temperatures of Gansu's Major Cities (in Centigrade)
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| Lanzhou | - 6.8 | -2.1 | 5.5 | 12.0 | 17.0 | 20.0 | 22.6 | 21.2 | 16.1 | 9.8 | 1.6 | 5.4 |
| Jiayuguan | -9.7 | -6.3 | 1.6 | 9.7 | 16.5 | 20.5 | 23.1 | 21.8 | 15.7 | 7.9 | 0.8 | 7.8 |
| Dunhuang | -9.2 | -4.1 | 4.9 | 12.4 | 18.3 | 23.0 | 25.0 | 23.8 | 17.0 | 8.7 | -0.2 | -7.1 |
| Jiuquan | -9.4 | -5.2 | -2.0 | 9.9 | 16.2 | 20.9 | 22.8 | 21.4 | 15.6 | 8.2 | -1.0 | -7.8 |
| Tianshui | -2.1 | 0.2 | 6.3 | 11.7 | 17.7 | 21.1 | 23.3 | 21.7 | 16.3 | 11.3 | 3.9 | -1.8 |
| Xiahe | -12.0 | -10.0 | -10.0 | -2.0 | 5.0 | 7.0 | 12.0 | 15.0 | 10.0 | 0.0 | -0.5 | -0.8 |