How do you know a heat wave is happening?

Answer 1

You know when a heat wave is happening when you don't hear people saying, "Wow! Look at the cool wave!"

Seriously though, just listen to the daily weather. They have kept records on temperatures for 100 years. A weather record computer database program is setup to give alerts to the weather folks whenever a new trend is recognized be it temperature, precipitation, etc.

Answer 2

A heat wave is typically identified by unusually high temperatures persisting for an extended period, often exceeding historical averages for a specific region. Meteorological agencies measure temperatures and issue alerts based on predefined criteria to warn the public about the heat wave. Additionally, observations of human health impacts, such as heat-related illnesses and deaths, can also indicate the occurrence of a heat wave.