This wind chill calculator shows how cold it feels on exposed skin when wind is combined with low temperatures. It uses the formula adopted by the US National Weather Service and Environment Canada in 2001.
Wind chill formula
°F and mph: WC = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16
°C and km/h: WC = 13.12 + 0.6215T − 11.37V^0.16 + 0.3965TV^0.16
The formula applies only at or below 50°F (10°C) with wind of at least 3 mph (4.8 km/h).
Worked example
At 5°F with a 20 mph wind, the wind chill is about −15°F (−26°C), 20 degrees colder than the air temperature.
Frequently asked questions
Can wind chill freeze water or cool a car below air temperature?
No. Wind chill describes heat loss from skin. Objects cool faster in wind but never below the actual air temperature.
When does frostbite become a risk?
At wind chills around −18°F (−28°C), exposed skin can freeze in about 30 minutes, and much faster at colder values.