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humidity

American  
[hyoo-mid-i-tee, yoo-] / hjuˈmɪd ɪ ti, ju- /

noun

  • humidities
    plural
  1. humid condition; moistness; dampness.

  2. relative humidity.

  3. an uncomfortably high amount of relative humidity.

    It's not the heat, it's the humidity that tires me out.


humidity British  
/ hjuːˈmɪdɪtɪ /

noun

  1. the state of being humid; dampness

  2. a measure of the amount of moisture in the air See relative humidity absolute humidity

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

humidity Scientific  
/ hyo̅o̅-mĭdĭ-tē /
  1. The amount of water vapor in the atmosphere, usually expressed as either absolute humidity or relative humidity.


humidity Cultural  
  1. The amount of water vapor in the air. Humidity is measured in two ways: (1) Absolute humidity is the percentage of water vapor actually present in the air. (2) Relative humidity is the absolute humidity divided by the amount of water that could be present in the air. Relative humidity indicates the degree of comfort or discomfort one feels from the humidity, because it indicates the amount of perspiration that can evaporate from the skin.


Usage

What does humidity mean? Humidity is the state of air when it’s full of water vapor. Humidity is the noun form of the adjective humid, which is used to describe moist air—air that’s full of water vapor. Humidity is most commonly used in reference to weather or the general climate of a place, especially when the temperature is hot. Example: The humidity here in summertime is almost unbearable.

Other Word Forms

Noun Inflected Forms

Etymology

Origin of humidity

First recorded in 1350–1400; Middle English humydite, from Latin (h)ūmiditās; equivalent to humid + -ity

Compare meaning

How does humidity compare to similar and commonly confused words? Explore the most common comparisons:

Explanation

Humidity has to do with how much moisture is in the air. High humidity is a lot of moisture; low humidity is not much at all. Humidity is a word you'll hear if you watch a weather report, and it's also something people love to complain about. When it's hot and there's a lot of humidity, people sweat a lot — it's uncomfortable, sticky, and your hair is likely to frizz. When the humidity gets really high, there's going to be some rain or snow. In some parts of the country, people have a saying about yucky summer weather: "It's not the heat — it's the humidity."

Keep Reading on Vocabulary.com

Vocabulary lists containing humidity

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

In 2025, Kazakhstan's Turkestan region experienced eight months without rain and very low humidity levels, regional agricultural official Kazbek Bedebayev told AFP.

From Barron's Aug. 12, 2026

Temperatures in the area were in the lower 90s, and humidity levels were aboutaround 18% around the time of ignition.

From Los Angeles Times Aug. 8, 2026

The archaeologists built sterile, temporary structures with temperature and humidity controls, and lowered experts clad in head-to-toe medical gowns into the pits atop bedlike platforms so as to minimize contact with the artifacts.

From The Wall Street Journal Aug. 8, 2026

"He researched his weather app to predict a day that would have 'high winds, low humidity, sort of high heat,'" the affidavit said.

From BBC Aug. 7, 2026

Mid-morning, it was at least ninety-five degrees, the air leaden with humidity.

From "Zeitoun" by Dave Eggers

The air is forecast to be extremely dry, with relative humidities under 10% through Friday.

From Los Angeles Times Jan. 22, 2025

Because evaporation can occur continuously over a wide range of temperatures and humidities -- and even at night -- there are many exciting potential applications for more efficient HV devices.

From Science Daily Mar. 6, 2024

By dehydrating mushrooms or measuring their cooling ability at different air humidities, the researchers determined that the chilling effect stems from water evaporating from the fungi—the equivalent of sweating on a hot day.

From Science Magazine May 5, 2023

“It did bring rain, it did bring higher humidities, and of course that’s always a blessing when it comes to fires,” said Cal Fire Battalion Chief Issac Sanchez.

From Washington Times Sep. 10, 2022

Relative humidities follow an inverse relationship to air temperatures; when air temperatures are highest, relative humidities approach their lowest values.

From Comparative Ecology of Pinyon Mice and Deer Mice in Mesa Verde National Park, Colorado by Charles L. Douglas

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