In A Nutshell
Wind chill is a mathematically derived number designed to let us know what the outdoor temperature feels like to our human skin, not how it affects the mercury in a thermometer. Some want to do away with it, arguing that a limited formula can’t accurately predict how the weather will “feel” to every person in their own unique environment. Those who support it say that even with its flaws, the wind chill still gives folks a better idea of what to expect before they go outside. For those with strong opinions on the matter, the debate rages on.
The Whole Bushel
With each new year it seems the wind chill temperature gets greater coverage and is talked about more than the actual air temperature. While some think reporting on the wind chill gives us a better idea of what we’ll experience when we go outside, others think the whole notion of a perceived wind chill is a bunch of malarkey based on loose science.
To appreciate both sides of the debate, we have to first understand what “wind chill” really means. Despite what some may believe, it has no influence on the air temperature and, no matter how low the wind chill gets, it can’t cause water or anything else to freeze if the legitmate temperature is still above 0 degrees Celsius (32 °F). At its core, wind chill simply describes the rate of heat loss from a human body exposed to particular weather. Because wind blows away bodily surface heat, our body temp drops faster as the wind speeds up (kind of like blowing on a hot bowl of soup). Over time, meteorologists have added more variables to the basic wind chill equation (which originally was only based on wind speed and air temperature) to approximate how cold a person’s skin will feel when they go outside—this is the modern type of wind chill reported on weather stations.
As wind chill detractors point out, however, there are some problems with the modern wind chill equation. Most importantly, it can’t account for all the different human and environmental variables. The wind chill is currently calculated based on a person who is somewhat chubby, 150 centimeters (5 ft) tall, and walking at a normal pace into the wind. Obviously, this doesn’t even portray the average person. Not to mention, it doesn’t take into account solar radiation, which can make us feel 10 to 15 degrees (Fahrenheit) warmer. Nor does it consider any buildings, obstacles that might block some of the wind, our fat levels, or our genders. Making matters worse, there’s no universally agreed-upon standard for how to calculate wind chill, meaning different countries use varying standards.
The other major argument against wind chill is it confuses people about what’s really going on outside and the actual temperature of their skin. Despite popular opinion, our skin temperature cannot be less than the ambient air temperature, no matter how low the wind chill. So, although our bodies will cool down faster when the wind chill plummets, we’re not at risk of frostbite until the real temperature dips below freezing. Regardless of how long we stay outdoors or how extreme the wind chill, our skin will only freeze if the air temperature is freezing, and usually it takes even lower temps than that for frostbite to occur. For some, the overall confusion and imprecise equation are reason enough to get rid of the wind chill altogether.
Those on the other side of the debate argue that, although the wind chill has some shortcomings, it still helps people be more prepared for extreme weather. They claim it makes people more cautious, encourages them to bundle up during low wind chills, and ultimately boosts safety. Furthermore, frostbite sets in faster when the wind chill is lower than the real temperature (assuming it’s below freezing), so it’s important to make people aware of such conditions. On the whole, most wind chill advocates recognize that it’s not a perfect system and perhaps somewhat subjective, but at least it lets folks know that not every brisk day feels the same.
But, no matter what side we support in the wind chill debate, one thing is for sure: It’s probably not going anywhere soon. How else would alarmist weathermen get viewers excited about yet another cold day in the dead of winter? And it still comes in handy when people try to emphasize how much more miserable their city is compared to their friend’s.