Why is the air pressure on a sunny day higher than that on a cloudy day?

When the temperature is high, the air pressure is low, and when the temperature is low, the air pressure is high. (The air pressure here should be the surface air pressure) When the temperature is high, the hot surface air runs upward, so the surface air pressure is low. (As the air goes up, of course the surface pressure is low.) The air condenses (with a certain humidity) as it rises, forming clouds and rain. When the temperature is low, the cold air in the upper layer goes downwards and pressurizes the surface. So the surface pressure is high.