Wind Chill Calculator
Calculate wind chill temperature using the official NWS formula. See frostbite risk time and danger level from air temperature and wind speed.
Quick Answer
Wind chill makes it feel colder than the actual temperature. At 20°F with 15 mph wind, it feels like 6°F. Below -20°F wind chill, frostbite can occur in under 30 minutes.
Calculate Wind Chill
Enter air temperature and wind speed. Valid for temps ≤ 50°F (10°C) and wind ≥ 3 mph.
Wind Chill Chart (°F)
Air temperature across the top, wind speed down the left side.
| mph \ °F | 40 | 30 | 20 | 10 | 0 | -10 | -20 | -30 | -40 |
|---|---|---|---|---|---|---|---|---|---|
| 5 | 36 | 25 | 13 | 1 | -11 | -22 | -34 | -46 | -57 |
| 10 | 34 | 21 | 9 | -4 | -16 | -28 | -41 | -53 | -66 |
| 15 | 32 | 19 | 6 | -7 | -19 | -32 | -45 | -58 | -71 |
| 20 | 30 | 17 | 4 | -9 | -22 | -35 | -48 | -61 | -74 |
| 25 | 29 | 16 | 3 | -11 | -24 | -37 | -51 | -64 | -78 |
| 30 | 28 | 15 | 1 | -12 | -26 | -39 | -53 | -67 | -80 |
| 35 | 28 | 14 | 0 | -14 | -27 | -41 | -55 | -69 | -82 |
| 40 | 27 | 13 | -1 | -15 | -29 | -43 | -57 | -71 | -84 |
| 45 | 26 | 12 | -2 | -16 | -30 | -44 | -58 | -72 | -86 |
About This Tool
The Wind Chill Calculator uses the official National Weather Service (NWS) formula to calculate the "feels like" temperature based on air temperature and wind speed. It displays the wind chill value, frostbite risk timeline, and a danger level assessment to help you make safe decisions about outdoor exposure in cold, windy conditions.
The NWS Wind Chill Formula
The current NWS wind chill formula was adopted in 2001 and is based on advances in heat transfer theory, wind tunnel testing on human subjects, and clinical data. It replaced the Siple-Passel formula from the 1940s which produced lower wind chill values. The formula is: Wind Chill = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16), where T is temperature in °F and V is wind speed in mph at 5 feet above ground.
When Wind Chill Matters Most
Wind chill is most relevant for outdoor workers, athletes, hikers, and anyone spending extended time outdoors in cold weather. It is especially important for children and elderly people, who are more susceptible to cold injuries. Wind chill advisories are issued when conditions could lead to frostbite or hypothermia, even for people who are properly dressed. Always check the wind chill forecast before planning winter outdoor activities.
Protecting Yourself
In high wind chill conditions: cover all exposed skin (especially face, ears, fingers, and toes), dress in wind-resistant outer layers with insulating layers underneath, stay dry (wet clothing loses insulation), limit outdoor exposure time, and watch for signs of frostbite (numbness, white or grayish skin) and hypothermia (shivering, confusion, drowsiness). If you must be outdoors, take frequent warming breaks.
Frequently Asked Questions
What is wind chill?
What is the NWS wind chill formula?
At what wind chill is it dangerous to go outside?
Does wind chill affect objects or only people?
What is frostbite and how does wind chill cause it?
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