Why is it sultry before it rains?

Before the rain, the clouds were low and covered in the air like quilts.

Because of the rich water vapor and high air humidity in summer, when the temperature is not too high (relatively speaking), people feel sultry, just like in a steamer. Such weather is called sultry and high temperature. Because people like to take a sauna in this weather, it is also called "sauna day".

If the heat and moisture in the air cannot be released, the air will be sultry. In addition, people's sweat doesn't like to dry, and sweat can't spread out of the body quickly, so it feels particularly stuffy.