Wind Chill Calculator
Calculate the wind chill (feels-like) temperature from air temperature and wind speed.
Supports Fahrenheit/Celsius and mph/km/h.
How Wind Chill Is Calculated
Wind chill is the perceived decrease in air temperature felt by the body due to wind. Moving air accelerates convective heat loss from exposed skin, making it feel colder than the actual air temperature without changing the actual thermometer reading.
NWS Wind Chill formula (North American standard, revised 2001):
Wind Chill (°F) = 35.74 + 0.6215 × T − 35.75 × V^0.16 + 0.4275 × T × V^0.16
Where:
- T = Air temperature in °F
- V = Wind speed in mph
Worked example:
- Temperature: 20°F
- Wind speed: 25 mph
WC = 35.74 + (0.6215 × 20) − (35.75 × 25^0.16) + (0.4275 × 20 × 25^0.16) 25^0.16 ≈ 1.954 WC = 35.74 + 12.43 − 69.85 + 16.71 = −4.97°F ≈ −5°F
Wind chill quick reference (°F):
| Air Temp | 10 mph | 20 mph | 30 mph |
|---|---|---|---|
| 30°F | 21°F | 17°F | 15°F |
| 20°F | 9°F | 4°F | 1°F |
| 10°F | −4°F | −9°F | −12°F |
| 0°F | −16°F | −22°F | −26°F |
Frostbite risk thresholds:
- 30 minutes at −18°F wind chill (−28°C)
- 10 minutes at −40°F wind chill (−40°C)
- 5 minutes at −60°F wind chill (−51°C) — rare but possible in Arctic air masses
Key limitations:
- Wind chill applies to bare skin only — proper clothing significantly changes real heat loss
- Does NOT affect inanimate objects — pipes don’t freeze faster due to wind if the air is above 32°F
- Wind chill cannot push the perceived temperature below the ambient air temperature on exposed objects