heat wave

American  

[heet weyv] / ˈhit ˌweɪv /

Or heatwave

noun

Meteorology, Climatology.

1. a period of abnormally hot and usually humid weather; heat event.

   I moved to the coast up north because summer back home has become one long, unbearable heat wave.

2. an air mass of high temperature covering an extended area and moving relatively slowly.

   Another heat wave is expected to form across the South and into the Northeast by week’s end.

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heat wave British  

noun

1. a continuous spell of abnormally hot weather

2. (not in technical use) an extensive slow-moving air mass at a relatively high temperature

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Etymology

Origin of heat wave

First recorded in 1875–80

Example Sentences

The ongoing heat wave shattering dozens of temperature records in Southern California is no exception, Swain said.

From Los Angeles Times • Mar. 20, 2026

It’s finally expected to cool down in Southern California this weekend after a scorching heat wave this week broke temperature records across the region.

From Los Angeles Times • Mar. 20, 2026

The unusual early heat wave is heightening concerns about public safety and marks a test of the state’s efforts to combat heat-related deaths in a time of rising temperatures.

From Los Angeles Times • Mar. 17, 2026

A record-breaking heat wave will scorch Southern California this week, raising temperatures up to 35 degrees above normal for March and heightening concerns about heat-related illness and deaths.

From Los Angeles Times • Mar. 16, 2026

During the heat wave, Chicagoans were advised to cool off at the beach.

From "A Few Red Drops: The Chicago Race Riot of 1919" by Claire Hartfield

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