Humidity affects how hot or cold a day feels. Absolute humidity is the amount of water in the air, while relative humidity is the ratio of actual water to total possible water. Higher humidity can make hot days feel hotter and cold days feel colder. Wind and individual sensitivity also play a role.
Many people note that hot, muggy days somehow feel much hotter than dry heat days. One reason is humidity, the amount of water in the air. When the air holds more water, the all-important act of perspiration or sweating is less efficient at cooling the body. More water in the air means less water can evaporate from the skin and most people will end up feeling hotter. Some of the ways humidity is measured are by measuring absolute humidity and relative humidity, which is often how people tell how “humid” a day will be.
First, it’s important to understand that air can only hold a certain amount of water at any given time. This measurement is absolute humidity, and absolute humidity depends on air temperature. In many circumstances, actual air holds much less water than it technically could, so the relative term comes into play. When meteorologists discuss relative humidity, they usually do so in percentage amounts, and this percentage is a ratio of how much water the air holds versus how much water it could hold. The effective formula is the amount of water (actual vapor density) divided by the amount of total possible water (saturated vapor density) times 100%. Most people will see the expression of this formula often in relative humidity counts when they look at or read weather reports.
That percentage or a day’s relative humidity can tell people how hot they can feel under certain circumstances. Dryer air may not feel as warm in warmer temperatures. Air at about 45% relative humidity will feel more like the outside temperature. Anything above this level can make the day feel hotter than it actually is at certain temperatures.
The perception of temperature can be influenced by relative humidity in reverse. On cold days, usually ones below 53 degrees F (11.67 degrees C), higher humidity can actually make people feel colder than they normally would. Although other factors such as wind chill can influence the “feeling of temperature” and perception, the relative humidity in the cold season can also be an important factor. Freezing weather with a relative humidity close to 100% can be much colder than freezing weather with a lower humidity level.
Relative humidity measurement can’t be the only determination of how the weather will feel; the amount of wind, especially in colder temperatures and other factors come into play. Furthermore, individuals may be more or less sensitive to certain temperatures. However, it’s a good way to determine how hot or cold a day might be.
Protect your devices with Threat Protection by NordVPN
