Post #16

What is humidity? Humidity is the amount of water vapor in the air. Too much or too little humidity can be dangerous. Humidity plays an important role in our daily weather. Without water vapor in the air, our weather might be like the weather on Mars. How does humidity affect us on a hot day? Humans are sensitive to changes in humidity, because our skin uses the air around us to get rid of moisture in the form of sweat. If the relative humidity* is very high, the air is already saturated with water vapor and our sweat won't evaporate. When this happens, we feel hotter than the actual temperature. Likewise, very low humidity can make us feel cooler than the actual temperature. This happens because the dry air helps sweat evaporate more quickly than usual. If the temperature outside is 24° C, humidity can make it feel warmer or cooler. A relative humidity of 0% would make it feel like it's only 20.5° C. On the other hand, a relative humidity of 100% would make it feel like it's 26.5° C. So what's a comfortable humidity level? Studies have shown that we tend to feel most comfortable at a relative humidity of around 45%. Some people use special machines called humidifiers (add humidity) or dehumidifiers (remove humidity) to keep indoor humidity at a comfortable level. *check the first comment #science