heat wave

American  

[heet weyv] / ˈhit ˌweɪv /

Or heatwave

noun

Meteorology, Climatology.

• heat waves
  plural

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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Other Word Forms

Noun Inflected Forms

• heat waves
  plural

Etymology

Origin of heat wave

First recorded in 1875–80

Example Sentences

See Examples For:

heat wave

Temperatures in the ocean around Southern California are higher due to a longstanding and unusual marine heat wave but are generally in the high 60s or low 70s.

From Los Angeles Times ● Sep. 1, 2026

The summer also doubled the previous record number of days above 34 degrees Celsius, or 93 Fahrenheit—14 versus seven in 1976, the year of a notorious heat wave.

From The Wall Street Journal ● Aug. 31, 2026

A family of black bears are safe after being rescued from a large water tank in La Verne amid a dangerous heat wave in Los Angeles, according to L.A.

From Los Angeles Times ● Aug. 30, 2026

Over in San Francisco, which faced down a severe heat wave in March, Google Weather users were left flummoxed by the charts of low-70s temps, way milder than the 90-degree record felt by downtown residents.

From Slate ● Aug. 21, 2026

And yet even as he embraced that bleak understanding, on this, the worst day of the winter, he recalled something he’d seen on the worst day of the worst heat wave of the summer.

From "Typical American" by Gish Jen

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