In the depths of Inland China, Dunhuang has a very dry climate. It has four special characteristics. The first is lots of direct sunshine. The second is little rainfall. The annual average rainfall here is only 39.9 mm. The third is the climate's four distinct seasons. Winter and summer have huge temperature differences . Lastly, sand storms can be a problem in the Dunhuang , with the wind sometimes reaching speeds of 3m/sec . The best time to visit Dunhuang and the ancient Silk Road is from May to October.