Wind Chill Calculator
Calculate how cold it really feels based on temperature and wind speed
How to Use This Wind Chill Calculator
- Enter the current air temperature (from thermometer or weather app)
- Select Fahrenheit or Celsius based on your preference
- Enter the wind speed (check weather reports or use an anemometer)
- Select your wind speed unit (mph, km/h, knots, or m/s)
- Click 'Calculate Wind Chill' to see the feels-like temperature and frostbite risk
Example: At 20°F with 25 mph wind: wind chill is 3°F, a 17-degree drop. Frostbite can occur on exposed skin in about 30 minutes. Dress accordingly.
Tip: The frostbite timer helps you plan outdoor activities—set a reminder to take warming breaks before the danger threshold.
Why Use a Wind Chill Calculator?
Wind chill tells you how cold it actually feels on exposed skin, which is what matters for dressing appropriately and staying safe.
- Decide what to wear before heading outside in winter
- Plan outdoor activities like skiing, hiking, or football games
- Assess safety for outdoor workers and construction crews
- Determine whether to cancel outdoor school recess
- Prepare for winter camping or mountaineering trips
- Protect pets and livestock during cold weather
Understanding Your Results
Wind chill temperature determines your frostbite risk and how quickly you need to seek shelter.
| Result | Meaning | Action |
|---|---|---|
| Above 0°F (-18°C) | Low risk | Frostbite possible in 30+ minutes; dress warmly for comfort |
| 0°F to -17°F | Moderate risk | Frostbite in 10-30 minutes; cover all exposed skin |
| -18°F to -40°F | High risk | Frostbite in 5-10 minutes; limit exposure, take frequent breaks |
| Below -40°F | Extreme danger | Frostbite in under 5 minutes; avoid outdoor exposure entirely |
Meaning: Low risk
Action: Frostbite possible in 30+ minutes; dress warmly for comfort
Meaning: Moderate risk
Action: Frostbite in 10-30 minutes; cover all exposed skin
Meaning: High risk
Action: Frostbite in 5-10 minutes; limit exposure, take frequent breaks
Meaning: Extreme danger
Action: Frostbite in under 5 minutes; avoid outdoor exposure entirely
Note: Wind chill affects living tissue, not inanimate objects. Your car won't freeze faster due to wind chill, but you will.
About Wind Chill Calculator
Formula
Wind Chill (°F) = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16) Where T is air temperature in Fahrenheit and V is wind speed in mph. This formula is valid when temperature is at or below 50°F and wind speed exceeds 3 mph.
Current Standards: The National Weather Service adopted the current formula in 2001, replacing the older Siple-Passel formula that overestimated wind chill. Canada uses the same formula. The new formula better reflects actual heat loss from exposed face.
Frequently Asked Questions
Does wind chill affect my car or home?
No. Wind chill only affects exposed skin. Your car, pipes, and home respond only to actual air temperature. However, wind does increase the rate at which objects cool DOWN to the ambient temperature—so your car cools faster in wind, but not colder than the actual temperature.
Why doesn't wind chill apply above 50°F?
The formula was designed for cold-weather safety. Above 50°F, the 'feels like' temperature is influenced more by humidity (heat index) than wind. At moderate temperatures, wind actually feels refreshing rather than dangerous, so a different calculation applies.
How accurate is this wind chill calculator?
This calculator uses the official NWS formula, which was validated through clinical trials. However, personal factors affect your experience: wet skin, alcohol consumption, fatigue, and health conditions can make you lose heat faster than predicted. The frostbite times are averages for healthy adults.
What's the coldest wind chill ever recorded?
Antarctica has recorded wind chills below -130°F. In the continental US, Mount Washington has seen wind chills as low as -103°F. At these temperatures, exposed flesh freezes in under 30 seconds. The combination of -40°F air with 50+ mph winds creates these dangerous conditions.
How do I protect myself in extreme wind chill?
Layer with moisture-wicking base layers, insulating mid-layers, and wind-blocking outer layers. Cover all exposed skin—ears, nose, and fingers are most vulnerable. Wear insulated, waterproof boots. Take breaks every 10-15 minutes in extreme conditions. Watch for frostbite signs: numbness, white or gray skin patches.