Why is the daily temperature difference in Guiyang smaller than that in Kunming?

There is a quasi-static front in Kunming of Yunnan-Guizhou Plateau in winter and spring, Guiyang is on the cold air side and Kunming is on the warm air side. Because the warm air rises above the cold air, it is forced to rise above Guiyang. Because the rising and cooling become clouds, Guiyang is rainy, while Kunming only controls the warm air, which is sunny. Finally, the daily temperature difference in Guiyang is smaller than that in Kunming.