Weather calculator
Calculate Wind Chill and How Fast Frostbite Can Set In
Wind chill
-9°F (-23°C)
Frostbite on exposed skin
Low risk for most people
How the wind chill calculator works
Wind chill is how cold it feels on exposed skin, because moving air strips heat away faster than still air. This calculator uses the formula the US National Weather Service and Environment Canada adopted in 2001, which is based on heat loss from the face at walking speed.
WC = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16 T in °F, V in mph at 10 m height Valid for T ≤ 50°F and V ≥ 3 mphQuick tips
- Wind chill only applies to skin. It will not cool a car engine or a water pipe below the actual air temperature.
- Cover the face first. Cheeks, nose and ears are where frostbite starts, and the formula is built around the face.
- Above 50°F (10°C) it does not apply. In warm weather, wind makes you feel cooler, but that is not what wind chill measures.
Approximate frostbite risk by wind chill (NWS)
| Wind chill | Time for frostbite on exposed skin |
|---|---|
| Above -18°F (-28°C) | Low risk for most people |
| -18°F to -32°F (-28°C to -36°C) | About 30 minutes |
| -33°F to -47°F (-36°C to -44°C) | About 10 minutes |
| -48°F (-44°C) and colder | 5 minutes or less |
Frequently asked questions
What wind chill is dangerous?
Frostbite becomes a real risk once the wind chill reaches about -18°F (-28°C), where exposed skin can freeze in around 30 minutes. At -48°F (-44°C) and below it can happen in 5 minutes or less.
Why is there no wind chill above 50°F?
The 2001 formula was built and tested for cold conditions. Above 50°F (10°C) the heat-loss model no longer holds, so forecasters use the air temperature or the heat index instead.
Which wind speed should I enter?
The sustained wind from a forecast or weather station, which is measured about 10 m (33 ft) above the ground. Gusts are higher than the value the formula expects.