Windchill doesn’t tell you whether its freezing outside; it predicts if you’ll get frostbite.

Winter is the most difficult time of the year, despite the festive season that seems to fill our memories with delightful merry makings. However, if you want to survive the season of winter, you’ll surely have to face the risk of getting a frostbite once you’re out there in the freezing cold. Windchill seems to tell us more on how bad it freeze is out there. Spoiler: it doesn’t. Let’s explain!

Feeling Freezy? You Gotta Chill

Let’s say you wake up on one frigid winter morning, on your smartphone, the weather says the temperature is 3 degrees Celsius (38 degrees Fahrenheit), with an outside wind chill of -1 degree Celsius (31 degrees Fahrenheit). That’s freezy. So you take a look out the window to find what’s going on outside, it seems you can clearly see puddles of water. Not freezing. So you ask: “What the heck?”

This is what: It’s seems that wind chill doesn’t predict the weather as you’d expect, that it’s freezing outside; it just predicts a frostbite

Wind Chill Evolution

The whole concept of a “wind chill” factor evolved from the 1950s developed by a pair of American scientists working in Antarctica. They wanted to measure how wind was able to make objects lose heat more quickly than they would usually. To carry out this experiment, they used the solidly scientific method of leaving plastic water bottles on the roof of their hut — because they expressed this new metric in kilocalories per hour per square meter, it was mostly used by scientists until the 1960s.

However, the United States military back then noticed that such a measure might come in handy for their troops, and translated the metric into “equivalent temperature” — that is, degrees Fahrenheit (°F). That’s when it caught on like wildfire, appearing in TV and radio weather reports everywhere.

Moreover, this water-bottle metric seemed unrealistic to experiment on people, so the National Weather Service recruited scientists to revise the wind-chill formula by using experiments with real people. It was brilliant in it’s simplicity: If you know the temperature and wind speed outside, you can know your risk of getting a frostbite.

Weather You Feel It Or Not

But there’s a small catch: It entails a whole lot of things that’s probably not applicable to you. Wind chill only predicts your risk of getting a frostbite if you’re 170 centimeters (5 foot 6 inches), overweight, and the sun isn’t shining, there are no trees or buildings blocking the wind, walking steadily at a pace 4.5 kilometers per hour (3 miles per hour), and you’re heading straight into a headwind. Despite this glaring flaw and many calling to abandon the metric, the National Weather service still promotes wind chill as the be-all end-all.

Fortunately, weather app have better alternatives; if you have Accuweather, you can check it’s RealFeel temperature to know how it feels outside. And for a more scientific measure, try the Universal Thermal Climate Index (UTCI).

You’re probably not aware of how pretty frigid the weather might be before you get out, so always take maximum precautions and stay safe. Winter is coming.