Relative Humidity: A Key Weather Variable — Passage
Relative humidity is a measure of how much water vapor is in the air compared to the maximum amount the air can hold at a given temperature. It is expressed as a percentage. For example, if the relative humidity is 50%, the air contains half the water vapor it could hold at that temperature.
Relative humidity depends on both the amount of water vapor in the air and the air temperature. Warm air can hold more water vapor than cold air. When air cools, its relative humidity increases, even if the amount of water vapor stays the same. This is why dew forms on cool mornings.
Relative humidity is measured using a hygrometer. It is an important factor in weather forecasting because it affects cloud formation, precipitation, and how comfortable we feel. High relative humidity can make the air feel muggy, while low relative humidity can make it feel dry.
Relative humidity also plays a role in health and safety. High levels can promote mold growth, while low levels can cause dry skin and respiratory problems.
Fun fact: Relative humidity can reach 100% during foggy conditions, meaning the air is fully saturated with water vapor.
What is relative humidity?
The total amount of water vapor in the airA percentage of the maximum water vapor the air can holdThe speed of the windThe temperature of the airWhat does relative humidity depend on?
Air pressure and wind speedAmount of water vapor and air temperatureEarth’s rotation and moon’s gravityOcean currents and soil typeWhat instrument is used to measure relative humidity?
ThermometerBarometerHygrometerAnemometerWhat happens to relative humidity when air cools?
It decreasesIt increasesIt stays the sameIt becomes zeroWhat is one effect of high relative humidity?
The air feels dryThe air feels muggyIt causes respiratory problemsIt reduces mold growthWhat is the fun fact mentioned in the passage?
Relative humidity can reach 100% during fogRelative humidity is always 50%Relative humidity is not affected by temperatureHygrometers cannot measure relative humidityWhat is one role of relative humidity in weather forecasting?
It affects cloud formation and precipitationIt measures wind speedIt predicts earthquakesIt controls ocean currentsWhat is one health effect of low relative humidity?
It causes mold growthIt makes the air feel muggyIt causes dry skin and respiratory problemsIt increases sweat evaporationRelated Content
