Wind Chill Calculator

Wind chill is a measure of how cold the air feels on exposed human skin due to the combined effect of temperature and wind. It does not measure how cold inanimate objects get — a car will not freeze below the actual air temperature, but it will reach that temperature faster in wind. For hot-weather comfort, try our Heat Index Calculator.

The modern wind chill formula, adopted in 2001, is based on experiments with human volunteers in a wind tunnel. It calculates the rate of heat loss from exposed skin and translates that into an equivalent temperature under calm conditions. The formula is only valid at or below 50°F (10°C) with winds above 3 mph (5 km/h).

For cold-weather safety, dress in layers with a windproof outer shell. Cover all exposed skin when wind chill falls below 0°F (-18°C). At -20°F (-29°C) wind chill, frostbite can occur in 30 minutes on exposed skin. Check our Dew Point Calculator to understand how moisture also affects comfort.

• Dress in layers: A moisture-wicking base layer, insulating mid-layer, and windproof outer shell trap heat most effectively.
• Protect extremities: Fingers, toes, ears, and nose are most susceptible to frostbite. Wear insulated gloves, thick socks, and a face mask in extreme cold.
• Stay dry: Wet clothing loses most of its insulating value. Change out of wet clothes immediately.
• Know the signs: Numbness, white or grayish skin, and hard or waxy skin are early signs of frostbite. Warm the area gradually with body heat or lukewarm water.
• Stay hydrated: Dehydration increases hypothermia risk. Drink warm fluids and avoid alcohol, which causes blood vessels to dilate and increases heat loss.