What does 90% humidity mean?
Relative humidity is the ratio of the current absolute humidity to the highest possible absolute humidity (which depends on the current air temperature). A reading of 100 percent relative humidity means that the air is totally saturated with water vapor and cannot hold any more, creating the possibility of rain.
CALCULATING RELATIVE HUMIDITY. Calculating the RH requires the correct equation(s). The RH is the amount of moisture in the air (via moisture mass or vapor pressure) divided by the maximum amount of moisture that could exist in the air at a specific temperature (via max moisture mass or saturation vapor pressure).
- So you can have a change in relative humidity in one of two ways: 1) Change the amount of water vapor available; if there is liquid water present, for instance, a lake, you can have an increase in relative humidity by evaporation from the surface of the lake. You're adding water vapor, so the humidity increases.
- Relative humidity is the water-vapour content of the air relative to its content at saturation. Saturated air, for example, has a relative humidity of 100 percent, and near the Earth the relative humidity very rarely falls below 30 percent.
- Most people find dew points of less than 60 degrees comfortable. When the dew point rises above 65 degrees people will begin feeling that the air is “sticky.” As the dew points climb through the 70s the humidity bothers more and more people who are outdoors.
Saudi Arabia has the highest recorded dew point temperature. Humidity comes from water evaporating from lakes and oceans. Warmer water evaporates more quickly – that's why you find the most humid regions closer to warm bodies of water, like the Red Sea, the Persian Gulf and Miami.
- Relative humidity is the ratio of the current absolute humidity to the highest possible absolute humidity (which depends on the current air temperature). A reading of 100 percent relative humidity means that the air is totally saturated with water vapor and cannot hold any more, creating the possibility of rain.
- As moisture evaporates, it carries heat with it. When you waved the washcloth around in the air, water evaporated from it, taking heat with it and making the washcloth cooler. A similar thing happens in the air. When water vapor remains in the air as humidity, it makes the temperature feel warmer.
- During the winter, especially, humidity levels drop because cold air holds less moisture than warm air. Low humidity causes static electricity, dry skin and hair, increased susceptibility to colds and respiratory illness, and can allow viruses and germs to thrive.
Updated: 12th November 2019