Howdy! It’s Joey, back with more Fun Fact Friyay. Put on your winter coat for this one, even though we’re in the dog days of summer.

**Celsius and Fahrenheit temperatures intersect at -40 degrees.**

If you’ve been keeping up with previous issues, you’ve seen quite a bit of Olympic coverage around these parts. Now, we’re jumping right from the summer games into frigid temperatures. We’ll get an autumn-y fact in here at some point, don’t worry.

One time in college, I was playing basketball when an opponent dramatically jerked his head back to make a pass while I stood behind him. The collision cut open my face just under my eye. The resulting gash necessitated a hospital visit to get stitches.

The hospital seemed to be overcrowded, so they took my temperature in some sort of in-between waiting room. The reading came out in Celsius, and a man in the waiting room quickly calculated the correct Fahrenheit conversion. They checked his math, and he was right. What a smartie!

If my temperature had been -40 degrees Celsius, he would have had a very easy calculation to make. I would also have been very dead, so I’m glad the temperature was more in line with what a human body should be.

You may have learned the Celsius to Fahrenheit conversion (and vice versa) at some point, though it’s not the easiest to immediately calculate, especially if decimals are involved.

Here’s the gist:

To calculate Fahrenheit, take the Celsius temperature and multiply it by 9/5, or 1.8. Add 32, and that’s your Fahrenheit temperature.

To calculate Celsius, take the Fahrenheit temperature and subtract 32, then multiply by 5/9, or approximately .5556.

For example, 20 degrees Celsius is 68 degrees Fahrenheit (to show the work: 20 x 9 = 180, 180/5 = 36, 36 + 32 = 68).

If you were to draw a chart of these two measurements, Celsius and Fahrenheit would start converging as you decreased the temperature. 0 Celsius is 32 Fahrenheit, and you don’t need to be a math expert to know that 32 degrees is a smaller gap than 48 degrees.

Once you start getting really cold, those temperatures get even closer together. By the time you hit -40 degrees, it doesn’t matter if you’re measuring in Celsius or Fahrenheit — it’s the same temperature either way.

That’s the only instance where it happens. After that -40 degree point, the gap starts increasing again.

I sincerely hope you are never in a situation where the temperature is -40 degrees. But if you do, at least you can take comfort in the fact that you don’t need to clarify that you mean Fahrenheit or Celsius.

Interesting! I remember winter days growing up in Wisconsin when the temp was -20, though that may have been with the wind chill.

Regardless, one day it was -20 in WI and 80F in AZ where my uncle lived. That 100 degree difference was one factor in my decision to move to AZ!