The Heat Index. Is it Hot Enough for Ya?

I don’t know about you, but I seem to always take a moment to look at what the weather is going to be like for the day, or week, ahead.  I have lived in some hot areas of the world and I always get a little nasty feeling whenever a meteorologist mentions the heat and dramatically throws out the calculated heat index.  As if it isn’t hot enough already, it seems like the weather folks love to point out that you’ll be even more miserable than you thought.  And if you really look into how the heat index works, you will realize that it truly is a mathematical gauge for misery.

The heat index is calculated from a mathematical formula that combines the air temperature and the amount of water in the air to determine what the outside air temperature “feels” like if it were a dry day.  This doesn’t sound very exact, but it is pretty common that people notice that they sweat more and it “feels” hotter when there is a lot of humidity in the air.  An 85 degree day (we’re working with Fahrenheit for our example) with 80% humidity is going to “feel” miserably hot compared to a 90 degree day with 0% humidity.  Or, at least to a large sampling of the population, it would be miserable.

As an example of the extreme misery that the Heat Index can bring on to us, let’s take a look at a potential real life example:

Let’s say you live in the Everglades in Florida.  It’s not unusual to have a summer day in the mid 90’s. Because it’s a swampy area, it wouldn’t be unusual to have a high humidity in the air.  If you had a day that was 95 degrees Fahrenheit and 85% humidity, the heat index would tell you that your body will feel as though it is 140 degrees outside.  That is ridiculous!  In some parts of the world the heat index can get a lot further up there.

To learn more about how the heat index is calculated, follow these links:
Heat Index Calculator (Fahrenheit)     Heat Index Calculator (Celsius)

Although we talk about the heat index with mockery and disbelief, it is an important tool when preparing for hot days.  When the heat index is high, we need to keep very close watch on our bodies for threats of dehydration, heat stroke, and fatigue.

While the heat index likes to make us miserable when it’s hot out, its cousin, the wind chill factor, is also a gauge of what the temperature “feels” like to our sensitive bodies.  Unlike the heat index, wind chill is found from an equation that considers temperature and wind speed. 

Go to the Calcunation Temperature Menu to learn more about wind chill, temperature, and heat indices.

CalcuNATION is a website featuring online calculators and educational resources for mathematics.  Other Mathematical Blogs ( CalcuNATION on EduBlogs and CalcuNATION on Blogger)