- lightning too distant for thunder to be heard, observed as diffuse flashes near the horizon on summer evenings.
Origin of heat lightning
An Americanism dating back to 1825–35
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for heat lightning
Then the heat-lightning smile played about the hollow face again.
It reminded the other man of heat-lightning on a dark skyline.
It makes you feel like heat-lightning just to watch 'em fly!The Port of Adventure
Charles Norris Williamson and Alice Muriel Williamson
Mrs. Bolton kept a grim silence, against which her husband's babble of optimism played like heat-lightning on a night sky.Annie Kilburn
William Dean Howells
But now and then, for an instant, the post sprang into sight out of the blackness to the weird play of the heat-lightning.The Plow-Woman
- flashes of light seen near the horizon, esp on hot evenings: reflections of more distant lightning
- Intermittent flashes of reddish or orange light near the horizon, usually seen on a hot summer evening and unaccompanied by thunder. Heat lightning is thought to be the reflection of distant lightning on clouds. Its color is believed to be due to the refraction of light in the atmosphere. See also sheet lightning. See more at lightning.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.