Wind Chill Calculator
Calculate the feels-like temperature from air temperature and wind speed using the official NWS formula. Includes frostbite risk assessment and heat index for warm conditions.
Units
Frostbite Risk by Wind Chill
| Wind Chill (°C) | Wind Chill (°F) | Frostbite on Exposed Skin | Risk Level |
|---|---|---|---|
| 0 to −9 | 32 to 15 | Low risk | Low |
| −10 to −27 | 14 to −17 | Risk with prolonged exposure | Moderate |
| −28 to −39 | −18 to −38 | Frostbite in 10–30 min | High |
| −40 to −47 | −40 to −53 | Frostbite in 5–10 min | Very High |
| < −48 | < −54 | Frostbite in under 2 min | Extreme |
Frequently Asked Questions
Wind chill is the perceived decrease in air temperature felt by the body on exposed skin due to the flow of air. The NWS formula (used since 2001): Wind Chill (°F) = 35.74 + 0.6215×T − 35.75×V^0.16 + 0.4275×T×V^0.16, where T is air temperature in °F and V is wind speed in mph. It applies when T ≤ 50°F and V ≥ 3 mph.
Frostbite risk depends on both wind chill and exposure time. At wind chill −27°C (−17°F), frostbite can occur in 30 minutes. At −40°C (−40°F), frostbite can occur in 10 minutes. At −48°C (−55°F) or below, frostbite can occur in 5 minutes on exposed skin. Always cover exposed skin in extreme cold.
Wind chill measures how cold it feels due to wind in cold weather (T ≤ 50°F / 10°C). Heat index measures how hot it feels due to humidity in hot weather (T ≥ 80°F / 27°C). Both represent apparent temperature — how the human body perceives the conditions — rather than actual air temperature.
No. Wind chill only affects objects that generate their own heat, like the human body. A car engine or water pipe cannot cool below the actual air temperature due to wind chill. However, wind speeds up how quickly objects reach the ambient temperature — so pipes exposed to high winds will freeze faster than those sheltered.
NWS Wind Chill Formula
The current US/Canadian wind chill formula was adopted in 2001 and is based on a model of the human face cooled by walking into wind at 1.8 m/s (about 4 mph above ambient wind speed): WC(°F) = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16. In metric: WC(°C) = 13.12 + 0.6215T − 11.37V^0.16 + 0.3965TV^0.16, where T is °C and V is km/h.
Wind Chill Validity Range
The NWS formula is valid only when temperature is at or below 10°C (50°F) and wind speed is at least 4.8 km/h (3 mph). At higher temperatures or very low wind speeds, the result is not meaningful; the calculator shows "N/A" in those conditions.
- Wind chill is not a physical temperature — it cannot freeze water pipes faster than the ambient air
- Sunshine can increase the apparent temperature by 10–15°C above the wind chill value
- Wet or damp clothing dramatically accelerates heat loss beyond what wind chill predicts