Other forms: heat waves
A heat wave is a period of weather that's abnormally hot and humid. Temperatures during a heat wave can be dangerously high.
To be a heat wave, weather conditions must be much higher than normal for a particular region. What might be a typical summer temperature in south Texas would be considered a heat wave in the Pacific Northwest. People suffer during heat waves, and these weather conditions can also damage crops and increase the risk of wildfires. The first recorded use of heat wave to mean "unusually hot weather" was in 1890.