Wind Chill Calculator
Wind chill is calculated when temperature ≤ 50°F (10°C) and wind speed > 3 mph (5 km/h).
Wind Chill Index
Quick Reference
Related Calculators
Understanding Wind Chill
What is Wind Chill?
Wind chill describes how cold it actually feels on exposed skin when wind is factored in. Wind increases heat loss from your body by carrying away the warm air layer next to your skin. The faster the wind, the faster heat is carried away, and the colder it feels.
NWS Wind Chill Formula
Wind Chill Chart
| Temp/Wind | 5 mph | 10 mph | 15 mph | 20 mph | 25 mph |
|---|---|---|---|---|---|
| 40°F | 36 | 34 | 32 | 30 | 29 |
| 30°F | 25 | 21 | 19 | 17 | 16 |
| 20°F | 13 | 9 | 6 | 4 | 3 |
| 10°F | 1 | -4 | -7 | -9 | -11 |
| 0°F | -11 | -16 | -19 | -22 | -24 |
| -10°F | -22 | -28 | -32 | -35 | -37 |
Frostbite Risk
Frostbite Warning Signs
- Numbness or tingling
- Skin turns white or grayish
- Skin feels waxy or hard
- Clumsiness due to joint stiffness
Hypothermia Warning Signs
- Shivering (may stop if severe)
- Slurred speech
- Drowsiness or exhaustion
- Confusion or memory loss
Cold Weather Safety
Protection Tips
- Dress in layers—inner moisture-wicking, middle insulating, outer windproof
- Cover exposed skin, especially ears, nose, cheeks, and fingers
- Stay dry—wet clothing loses insulating properties
- Limit time outdoors when wind chill is dangerous
- Keep moving to maintain body heat
- Avoid alcohol—it increases heat loss
Wind Chill Advisory Levels
- Wind Chill Advisory: Wind chill between -15°F and -24°F for 3+ hours
- Wind Chill Warning: Wind chill at or below -25°F for 3+ hours
- Frostbite Warning: Exposed skin can freeze in 10-30 minutes
Frequently Asked Questions
What is wind chill and how is it calculated?
Wind chill is the perceived temperature when wind accelerates heat loss from exposed skin. The NWS formula: WC = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16), where T = air temp (F) and V = wind speed (mph). Only applies below 50F with wind over 3mph.
How fast can frostbite occur in cold weather?
Frostbite time depends on wind chill: at -10F feels-like, frostbite can occur in 30 minutes. At -25F, in 15 minutes. At -40F or below, frostbite can happen in as little as 5 minutes on exposed skin.
Why doesn't wind chill affect objects like cars?
Wind chill only applies to things that generate heat, like humans. Objects cool to air temperature regardless of wind - wind just speeds up the process. A car won't get colder than the actual air temp, but you will feel colder than the thermometer shows.
Is wind chill the same as 'feels like' temperature in summer?
No, summer 'feels like' is heat index, which factors humidity's effect on sweat evaporation. Wind chill is for cold: wind's effect on heat loss. Both measure perceived temperature but use completely different formulas and conditions.