A heat wave is a period of excessively hot weather, which may be accompanied by high humidity.
Definition
While definitions vary, a heat wave is generally measured relative to the usual weather in the area and relative to normal temperatures for the season.
High Pressure Domes
Heat waves often form when high pressure aloft (from 10,000–25,000 feet) strengthens and remains over a region for several days or weeks. This traps heat near the ground.
