Why is the temperature difference between day and night large in Xinjiang?

Because Xinjiang belongs to temperate continental climate, there are few water vapor and clouds in the air, which has a weak weakening effect on solar radiation during the day, and the solar radiation reaching the ground is strong and the temperature is high. At night, the atmosphere has a weak heat preservation effect on the ground, and the ground dissipates heat quickly and the temperature is low. Therefore, the temperature difference between day and night in temperate continental climate is so great.