What Exactly is the Heat Index?

With higher humidity present, it's going to feel hotter than the thermometers indicate. Here's a quick explanation of what we refer to as the "heat index".

Now that we've broken to the "other" side of Memorial Day, the days will be getting hotter and hotter while the humidity will climb higher and higher. You may notice the more frequent presence of muggy conditions and reference to the "heat index". What exactly is the heat index, anyway?

The heat index in summer is similar to what wind chill is to winter. The heat index is a measure of how hot it actually feels based on increased humidity. Humidity - or simply the moisture in the air - can make it feel significantly hotter to a person or living creature, and thus cause a faster onset of heat-related illnesses and problems.

As unsightly or smelly as it may be at times, your body's natural cooling mechanism is sweating.  When the sweat beads on your skin, it goes through evaporation - a cooling process. The evaporation of your sweat keeps your body temperature in check, much like the cooling system in a car. The more moisture / higher the humidity, the slower the sweat will evaporate on your skin. This will lead to a hotter feeling since your body isn't cooling as fast. For example, when the heat index is 100°, it feels like 100° to a human because the body is having a tougher time cooling due to all of the humidity in the air.

While the heat index applies only to living creatures, it is still to be taken seriously because high heat indicies can have an effect on one's health. If the human body can't cool fast enough, heat-prone illnesses may settle in at a faster rate. These illnesses may include fatigue, heat stroke, dehydration, and heat exhaustion. Therefore, it's extra important to keep cool and not overexert when the heat index climbs over the 100° mark.

With hot and humid times guaranteed to continue for several more months, the heat index will become a common part of our weathercasts. Stay safe - stay cool!

3, 2, 1, fade out...

Chief Meteorologist Travis Koshko

(This blog typed while listening to "Summer Breeze" by Seals and Crofts)

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