7 things you don't know about humidity
1. The humidity of 100% doesn't mean it's going to rain. Humidity is a physical quantity used to describe the amount of water vapor in the air. There are many ways to express air humidity, of which the most commonly used is the "relative humidity" in meteorology. So what is relative humidity? Let's think of air as a sponge. It can hold at most a certain amount of water, say 1 liter. Then the relative humidity refers to the ratio of the actual water content of the sponge (that is, absolute humidity) to the maximum amount of water that can be held. If the sponge does not drink water, the relative humidity is zero; if the sponge drinks 500 milliliters of water, the relative humidity is 50%. The maximum amount of water vapor the atmosphere can hold depends mainly on the temperature. A rise in temperature is equivalent to making the sponge bigger to hold more water. Therefore, when you increase the size of the sponge without adding more water, th...