DETROIT – What is the definition of a “heat wave”?
You hear it all the time when temperatures are about to rise: “A heat wave is heading toward the area.”
Recommended Videos
But what does it really mean?
National Weather Service offices actually set their own definitions for “heat waves.” So it’s different depending on where you are.
For Metro Detroit, the National Weather Service office in White Lake defines a heat wave as three consecutive days that reach 90 degrees or higher.
Some other offices define a heat wave as “a period of abnormally hot weather lasting more than two days.”
Obviously, not all heat waves are created equal. It can feel much hotter when the humidity is high, or when temperatures aren’t dropping below the 70s at night.
But now when you hear the term “heat wave,” you’ll know what it truly means: at least three days of major heat.


