Wind Chill Calculator

About the Wind Chill Calculator

A wind chill calculator determines the "feels like" temperature when wind increases the rate of heat loss from exposed human skin, making cold air feel significantly colder than the thermometer reading. Wind chill is a critical safety metric for outdoor workers, athletes, emergency responders, and anyone spending time outside in winter — it directly determines frostbite risk exposure times and hypothermia danger. At −20°F (−29°C) with a 30 mph wind, the wind chill temperature is approximately −60°F (−51°C) — conditions where frostbite can occur in as little as 5 minutes on exposed skin. The National Weather Service updated the wind chill formula in 2001 based on clinical studies using volunteer subjects in a wind tunnel, replacing the earlier less-accurate formula. Our calculator uses the current NWS formula and includes frostbite timing thresholds for quick risk assessment.

How It Works

NWS Wind Chill Formula (°F): WC = 35.74 + 0.6215T − 35.75(V^0.16) + 0.4275T(V^0.16), where T = air temperature in °F and V = wind speed in mph. The formula is valid for temperatures at or below 50°F and wind speeds above 3 mph. Below 3 mph, wind chill equals air temperature (insufficient wind to meaningfully accelerate heat loss). Celsius equivalent: WC (°C) = 13.12 + 0.6215T − 11.37(V^0.16) + 0.3965T(V^0.16) where V is km/h. Example: Temperature 10°F, wind 25 mph: WC = 35.74 + (0.6215×10) − 35.75(25^0.16) + 0.4275×10×(25^0.16) = 35.74 + 6.215 − 60.34 + 7.22 = −11.2°F. The 10°F day with 25 mph wind feels like −11°F.

Tips & Best Practices

• ✓Frostbite risk thresholds (NWS): Wind chill −10°F: frostbite in 30 minutes. Wind chill −30°F: frostbite in 10 minutes. Wind chill −60°F: frostbite in 5 minutes on exposed skin.
• ✓Wind chill only applies to living tissue: pipes, car engines, and other objects cool to the actual air temperature, not the wind chill temperature. Wind accelerates this cooling but the final temperature is still the air temperature, not lower.
• ✓Layering effectiveness: proper winter layering (moisture-wicking base, insulating mid-layer, wind-blocking outer shell) dramatically reduces the impact of wind chill by preventing convective heat loss.
• ✓Wet skin loses heat 25× faster than dry skin — staying dry in cold and windy conditions is critical for both comfort and preventing hypothermia.
• ✓School/outdoor event cancellation thresholds: many school districts cancel outdoor recess when wind chill falls below −15°F. Outdoor sports events are often cancelled below −20°F wind chill.
• ✓Wind chill and exercise: physical activity generates body heat that partially offsets wind chill effects. A runner generating significant metabolic heat can tolerate lower wind chill temperatures than a stationary person.
• ✓Wind direction relative to activity: facing into the wind creates higher effective wind chill than having the wind at your back. Cross-country skiers and cyclists experience significant wind chill even in calm conditions from self-generated movement through still air.
• ✓Canadian Wind Chill Index: Canada uses the same 2001 NWS formula but expresses results in °C and uses km/h for wind speed. The calculator converts between both country conventions.

Who Uses This Calculator

Outdoor workers in construction, utilities, agriculture, and emergency services assessing cold weather safety and deciding when to stop outdoor work. Parents and school administrators deciding whether outdoor activities are safe for children. Athletes and coaches planning cold-weather training sessions and competitions. Emergency management officials issuing public cold weather advisories. Weather enthusiasts and meteorology students understanding the physics of wind chill. Winter recreationists (skiers, snowshoers, snowmobilers) planning appropriate gear.