heat index
noun
plural heat indexes or heat indices
: a value that indicates what the ambient temperature feels like to the human body and that is derived from a calculation using air temperature and relative humidity
The most likely chances for a heat advisory are Thursday and Friday, when the heat index could approach at least 100 degrees, according to National Weather Service meteorologists …—
Julie E. Greene
Julie E. GreeneThe heat index is defined as a function of temperature and relative humidity. The combination of the two results in an apparent temperature that gives an idea of what the hot and humid air feels like to the average person.—Neil MacFarquhar
Neil MacFarquharExamples of heat index in a Sentence
Recent Examples on the Web
Schools with no air conditioning in gyms that are hotter than the outside heat index play PE-style games around desks in cooler classrooms.
—Bill Frist, Forbes, 22 Jan. 2025
In Caribou, Maine, for example, the NWS issued its first-ever excessive heat warning for a heat index near 110°F on June 19.
—Andrew Freedman, Axios, 15 Jan. 2025
An extreme heat belt is also emerging from Texas, bringing heat indexes of 110-115°F to Iowa.
—Linh Ta, Axios, 3 Jan. 2025
An excessive heat watch will be in effect across Indiana Tuesday with the possibility of heat index values of up to 107.
—Katie Wiseman Indianapolis Star, Indianapolis Star, 26 Aug. 2024
According to the weather service, the area can expect heat index values as high as 105.
—Diana Leyva, The Tennessean, 16 Aug. 2024
Her school's classrooms also don’t have air conditioning, and in some cases, no fans either — with a heat index that can reach over 115 degrees Fahrenheit.
—Valeria Ricciulli, refinery29.com, 25 Apr. 2024
How to stay safe during the Middle Tennessee heat wave
Nashville weather radar
7-day Weather forecast
Friday: Partly sunny, with a high near 93 and heat index values as high as 98.
—Diana Leyva, The Tennessean, 16 Aug. 2024
Related Articles Heat advisory in effect as heat index temps reach triple digits
Cramps?
—Cindy Krischer Goodman, Sun Sentinel, 19 July 2024
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Bill Frist, Forbes, 22 Jan. 2025
In Caribou, Maine, for example, the NWS issued its first-ever excessive heat warning for a heat index near 110°F on June 19.
—Andrew Freedman, Axios, 15 Jan. 2025
An extreme heat belt is also emerging from Texas, bringing heat indexes of 110-115°F to Iowa.
—Linh Ta, Axios, 3 Jan. 2025
An excessive heat watch will be in effect across Indiana Tuesday with the possibility of heat index values of up to 107.
—Katie Wiseman Indianapolis Star, Indianapolis Star, 26 Aug. 2024
According to the weather service, the area can expect heat index values as high as 105.
—Diana Leyva, The Tennessean, 16 Aug. 2024
Her school's classrooms also don’t have air conditioning, and in some cases, no fans either — with a heat index that can reach over 115 degrees Fahrenheit.
—Valeria Ricciulli, refinery29.com, 25 Apr. 2024
How to stay safe during the Middle Tennessee heat wave
Nashville weather radar
7-day Weather forecast
Friday: Partly sunny, with a high near 93 and heat index values as high as 98.
—Diana Leyva, The Tennessean, 16 Aug. 2024
Related Articles Heat advisory in effect as heat index temps reach triple digits
Cramps?
—Cindy Krischer Goodman, Sun Sentinel, 19 July 2024
Articles Related to heat index
Dictionary Entries Near heat index
Cite this Entry
“Heat index.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/heat%20index. Accessed 11 Feb. 2025.
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