Weatherz School: Wind chill explained

Every winter I hear people say, “Why don’t you just talk about the air temperature?” There is an important difference between air temp and wind chill, so let’s get into it.

Our bodies lose heat through convection. However, with little to no wind, a layer of that heat remains to help us stay warmer. With an outside temp of -14 and no wind, it feels like -14.

When it’s windy, moving air breaks up that insulating warm layer. This helps speed up heat loss, making it feel much colder. With a 20 mph wind, our -14 temp feels like -42. These are the conditions that were observed in Duluth Friday morning.

In these conditions, we lose heat at the rate we would if it were 28 degrees colder than it actually is. That’s a significant difference when it comes to how long it takes for hypothermia and frostbite to develop, and that’s why we care about wind chill.