The reason why the temperature difference between day and night on cloudy days is smaller than that on sunny days when other weather conditions are the same.

The temperature is related to ground radiation, and the intensity of ground radiation is related to solar radiation. On cloudy days, the ground absorbs less solar radiation, the ground radiation is weak, the temperature is low and the temperature difference between day and night is small. On sunny days, the ground absorbs more solar radiation, and the ground radiation is stronger, and the temperature is relatively high during the day, so the temperature difference between day and night is larger than that on cloudy days.