Why is it dry in winter?

When the temperature is high in summer, water easily evaporates into water vapor, so the more water vapor in the air, the more humid the air is. In winter, when the temperature is low, there is less water vapor in the air, making it dry.

In geography, we call the degree of dryness and humidity of the air "humidity".

Of course, the reason that makes the air dry in winter is not only the geographical reason that temperature affects the evaporation of water, but also:

1. For most parts of our country, there is less precipitation in winter, which can Less water evaporates into the atmosphere, making the air dry.

2. There is a limit to the amount of water vapor a certain amount of air can hold. We call it saturation, which means the relative humidity is 100%. The air with low temperature in winter can hold less water vapor, which means that even if enough water evaporates, the low-temperature atmosphere will appear dry.

3. There is also a physiological reason: in winter, after we inhale the air, the air is heated to body temperature, and the relative humidity will become very low (the same absolute humidity has different relative humidity at different temperatures) ), so we feel dry. The air we exhale is basically saturated steam at body temperature, so we consume a lot of water when breathing. The air near the skin will also be heated, so the moisture in the skin will also easily evaporate. These will make us feel very dry in winter.