Wind Chill Calculator
Wind strips away the thin layer of warm air your body maintains. Enter temperature and wind speed to see the feels-like value and how quickly exposed skin can freeze.
Frostbite risk at a glance
| Wind chill | Frostbite on exposed skin |
|---|---|
| Above 0°F | Low risk for brief exposure |
| −0 to −17°F | Possible with prolonged exposure |
| −18 to −31°F | In about 30 minutes |
| −32 to −47°F | In about 10 minutes |
| −48°F and below | In about 5 minutes or less |
What wind chill actually measures
Wind chill describes heat loss from exposed skin, not the actual air temperature. A thermometer outside reads the same whether it is calm or blowing a gale. What changes is how fast your body loses warmth, and the formula translates that into an equivalent calm-air temperature.
Two consequences follow. First, your car and your pipes respond to the real temperature, not the wind chill — wind cannot cool anything below the actual air temperature. Second, wind chill only applies to skin, so covering up genuinely removes most of the risk.
The formula
The current North American standard was adopted in 2001 after human trials with volunteers in a chilled wind tunnel. It applies when the temperature is at or below 50°F and wind exceeds 3 mph. Below that threshold the concept does not meaningfully apply, and this calculator will say so.
Staying safe in dangerous cold
Dress in layers, and prioritise covering fingers, ears, nose, and cheeks — the areas that freeze first. Mittens beat gloves. Watch for skin that turns white or grey and feels numb or waxy; that is frostbite starting, and it needs gradual rewarming, never rubbing or direct heat.
Shivering that stops, slurred speech, confusion, or drowsiness point to hypothermia, which is a medical emergency. Get the person somewhere warm, remove wet clothing, and call for help.