Text 1: Have you ever visited a place that just made you feel hot and sticky the entire time, no matter what you did to cool off? You can thank humidity for that unpleasant feeling.

Humidity is the amount of water vapor in the air. If there is a lot of water vapor in the air, the humidity will be high. The higher the humidity, the wetter it feels outside. On the weather reports, humidity is usually explained as relative humidity. Relative humidity is the amount of water vapor actually in the air, expressed as a percentage of the maximum amount of water vapor the air can hold at the same temperature.

Think of the atmosphere as a sponge that can hold a fixed amount of water, let's say a gallon of water. If there is no water in the sponge, then the relative humidity would be zero. Saturate the sponge with half a gallon of water - half of what it is capable of holding - and that relative humidity climbs to 50 percent. When humidity is high, the air is so clogged with water vapor that there isn't room for much else.

If you sweat when its humid, it can be hard to cool off because your sweat can't evaporate into the air like it needs to.

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