Wind chill calculator and time to frostbite
As of 2 November 2026, the US National Weather Service formula gives a wind chill of -19°F (-29°C) for 0°F (-18°C) air with a 15 mph (24 km/h) wind, and the NWS says exposed skin can freeze in 30 minutes at that wind chill; Environment and Climate Change Canada says exposed skin can freeze in 10 to 30 minutes at wind chills of -28°C to -39°C (about -18°F to -38°F) and in under 2 minutes at -55°C (-67°F) or colder.
Air temperature and wind
-19°F wind chill
High risk Exposed skin can freeze in 10 to 30 minutes (Environment and Climate Change Canada).
Rule: US National Weather Service, Wind Chill Chart and formula (effective 1 Nov 2001), checked 2026-11-02
Rule: Environment and Climate Change Canada, Wind chill and the Wind Chill Index, checked 2026-11-02
Frostbite time by wind chill
| Wind chill °C | °F (approx.) | Risk | Exposed skin can freeze in |
|---|---|---|---|
| 0 to -9 | 32 to 16 | Low risk | — |
| -10 to -27 | 14 to -17 | Moderate risk | — |
| -28 to -39 | -18 to -38 | High risk | 10 to 30 minutes |
| -40 to -47 | -40 to -53 | Very high risk | 5 to 10 minutes |
| -48 to -54 | -54 to -65 | Severe risk | 2 to 5 minutes |
| -55 or colder | -67 or colder | Extreme risk | less than 2 minutes |
Bands from Environment and Climate Change Canada (°C); °F columns are conversions. The NWS chart shows frostbite in 30 minutes from about -18°F to -24°F wind chill, depending on wind speed.
Worked examples · °F and mphWind chill by temperature and wind
| Wind \ Air | 30°F | 20°F | 10°F | 0°F | -10°F | -20°F | -30°F | -40°F |
|---|---|---|---|---|---|---|---|---|
| 5 mph | 25 | 13 | 1 | -11 | -22 | -34 | -46 | -57 |
| 10 mph | 21 | 9 | -4 | -16 | -28 | -41 | -53 | -66 |
| 15 mph | 19 | 6 | -7 | -19 | -32 | -45 | -58 | -71 |
| 20 mph | 17 | 4 | -9 | -22 | -35 | -48 | -61 | -74 |
| 30 mph | 15 | 1 | -12 | -26 | -39 | -53 | -67 | -80 |
| 40 mph | 13 | -1 | -15 | -29 | -43 | -57 | -71 | -84 |
| 50 mph | 12 | -3 | -17 | -31 | -45 | -60 | -74 | -88 |
Worked examples · °C and km/hWind chill by temperature and wind
| Wind \ Air | 5°C | 0°C | -5°C | -10°C | -15°C | -20°C | -25°C | -30°C | -35°C | -40°C |
|---|---|---|---|---|---|---|---|---|---|---|
| 10 km/h | 3 | -3 | -9 | -15 | -21 | -27 | -33 | -39 | -45 | -51 |
| 20 km/h | 1 | -5 | -12 | -18 | -24 | -30 | -37 | -43 | -49 | -56 |
| 30 km/h | 0 | -6 | -13 | -19 | -26 | -33 | -39 | -46 | -52 | -59 |
| 40 km/h | -1 | -7 | -14 | -21 | -27 | -34 | -41 | -47 | -54 | -61 |
| 50 km/h | -1 | -8 | -15 | -22 | -29 | -35 | -42 | -49 | -56 | -63 |
| 60 km/h | -2 | -9 | -16 | -23 | -30 | -36 | -43 | -50 | -57 | -64 |
Marked cells are wind chills where Environment and Climate Change Canada says exposed skin can freeze in 30 minutes or less.
Related on Global Incident Tracker
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What this page shows, and what it misses
Wind chill is how cold the air feels on bare skin when wind carries heat away. It does not change the air temperature, does not apply to cars or pipes, and is only defined at or below 50°F (10°C) with wind above 3 mph (4.8 km/h). Frostbite times are for exposed skin; wet skin, poor circulation, sunshine and clothing change them. For symptoms and treatment, follow your health service's advice.
Formula and chart: US National Weather Service (public domain). Hazard table: Environment and Climate Change Canada.