What's the climate like in Lanzhou, Gansu Province?

Compared with other cities, Lanzhou is a city with four distinct seasons/dusty in spring, cool in summer, sunny in autumn and not too cold in winter.

In the past, Lanzhou was seriously polluted, resulting in a lot of dust and bad weather. But in recent years, through the rectification of relevant departments and the maintenance of everyone, the air in Lanzhou has been greatly improved.

PS: Gansu is an underdeveloped province. Many resources have not been well utilized and developed.