Now that actual summer is finally here, I thought I’d take a moment to educate visitors and newbies to the area about “Heat Index” – a.k.a. “Why It Is So Freaking Hot Outside.”

In a nutshell: Humidity (water in the air) makes heat seem hotter.

Today, right now, the current air temperature is 93 degrees. Not bad, but I’ve seen worse. Down in the southwest you get higher degrees than this all the time. However, if you’ve ever been out there, you’ll notice one big difference – Humidity.

Humidity is expressed in percentages – 0% to 100%. These percents express how much water the air can hold at it’s current temperature. The hotter the air the more water it can hold. (”Dew” is what happens when night time air cools, reducing the amount of water it can hold. The excess drops on the ground.)

In the southwest the amount of water in the air is extremely low, even down to 0% at times. This effect is most noticeable when you step out of the sun. No matter how hot it gets the shade is always pleasant, and at night the temperature can drop to freezing (32 degrees) in the middle of the summer! Without water the air cannot hold heat.

Around here, however, we usually pull higher than 50% humidity. In fact, at our 93 degrees today we also have a 66% humidity. I found a Heat Index Calculator, which puts the Heat Index (”how hot it feels like”) at 112 degrees!

The point here is that, although it may feel like 112, it is in fact only 93 degrees. Every time you step out of the air conditioning and it feels like walking into a flaming brick wall, just tell yourself: “I, too, am mostly heated water, so this is no big deal. This… this is no big deal at all.”

Then go get yourself an ice cream and head on down to the local swimmin’ hole.

WORD ON THE STREET:

I’ve heard it said that an acre of corn or soybeans will evaporate more water than an open body of water (like a pond) of the same surface area. Anyone know if that’s true?

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