Wind Chill Calculator
Calculate the wind chill temperature from air temperature and wind speed.
Try an example
6.2°F
About this calculator
How This Wind Chill Calculator Works
Enter the air temperature and wind speed, and the calculator returns the wind chill — how cold exposed skin actually feels once wind is factored in.
Worked Example
At 20°F with a 15 mph wind, the wind chill is about 6.2°F — the air feels roughly 14 degrees colder than the thermometer alone suggests.
The Formula
Wind chill = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16, where T is air temperature in °F and V is wind speed in mph — the National Weather Service's official wind chill formula, developed from research on how quickly exposed facial skin loses heat in cold, windy conditions.
Why Wind Makes Cold Feel Colder
Skin naturally warms a thin layer of air right against it, which acts as light insulation. Wind continuously strips that layer away and replaces it with colder air, forcing the body to keep re-warming a fresh layer and accelerating heat loss. This is a real physical effect on heat loss, not just a subjective feeling — which is why wind chill is used to estimate frostbite risk on exposed skin, not just as a comfort index.
Why This Doesn't Apply to All Conditions
The formula is only defined for temperatures at or below 50°F and wind speeds of 3 mph or higher — above that temperature, wind doesn't meaningfully accelerate heat loss the same way, so the National Weather Service doesn't calculate a wind chill value.
Worked example
At 20°F with a 15 mph wind, the wind chill is about 6.2°F — the air feels roughly 14 degrees colder than the thermometer reading.
Frequently asked questions
Why doesn't wind chill apply above 50°F?
The formula was developed for cold-weather conditions, where wind meaningfully accelerates heat loss from skin. Above 50°F, wind doesn't have the same cooling effect, so the National Weather Service doesn't define a wind chill value there.
Is wind chill just about comfort, or is it a real temperature?
It's not a literal air temperature — it's an estimate of how quickly exposed skin loses heat, expressed in equivalent-feeling degrees. It's meaningful for assessing frostbite risk, not for things like how fast water would freeze.