The All-Important Heat Index

Seems like only yesterday we were talking about ice, record cold and wind chills, right? Believe it or not, we're now less than 3 weeks away from summer, with temperatures already feeling like they are there. Today and Wednesday we're watching the "heat index" numbers. But what is that?

Like the "wind chill" index, the heat index is what we consider a "feels like" or "apparent" temperature. That is, what the outside air feels like to you as you walk out the door. The heat index is a measure of the temperature and humidity levels combined. While the actual temperature is definitely important, you can relate more to the "feels like" temperature.

So how is this measured? Well, back in 1978 the heat index chart was invented by George Winterling (a retired TV meteorologist) and it was known then as the "humiture." It contained assumptions about human weight, height, mass and how we perceive the air on our skin. It even factored in clothing. Today, the National Weather Service has tweaked things to get a better grasp on how the humidity makes us feel under hot temperatures.

The more humid it is outside and the higher the temperature, the higher the heat index is. 80-90 degrees for example, can lead to fatigue- especially in folks who have heart conditions. On the other end, a heat index of 130+ would mean imminent heat stroke (hopefully something we'd NEVER see).

So this summer, not only will the temperature be important, but the heat index number too. See the chart attached for a better look at where the numbers stand!

Meteorologist Andrew Kozak

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