It is hot and dry in the summer. There is very little rainfall here in summer months and day-time temperatures can get above 100F (37C). The nighttime temperatures drop radically with the sunset so evenings can be cool to cold in the spring and fall. The winters are extreme with very cold temperatures and snow.
There's not much need to worry about rainfall at any time of year, so any time you visit it will be relatively dry. As long as you are prepared for the temperatures, any time of the year can be a great time to visit. Best bets are spring and autumn when the temperatures are milder.
What is Northwest China?The following areas and municipalities are considered to be in China's Northwest so will experience the kind of weather described above:
- Gansu Province & Dunhuang's Mogao Buddhist Grottoes
- Qinghai Province
- Shaanxi Province & Xi'an
- Ningxia Hui Autonomous Region
- Xinjiang Autonomous Region
Average Temperatures & Rainfall for Northwestern Chinese CitiesHere are some charts that will give you an idea of weather in cities in Northwestern China.
Urumuqi 10 Easy Travel Planning Steps to get started with your trip and read all about packing in my Complete Guide to China Packing.