Wind Chill Calculator
30°F with a 15 mph wind feels like 19°F. Enter the temperature and wind speed for the official feels-like number — and how fast frostbite becomes a risk.
Feels like
19°F
-7°C
Uses the NWS/Environment Canada 2001 formula, modeled on heat loss from a human face at walking speed. Wind doesn't make the air colder — it strips away your body's warm boundary layer faster, so you lose heat as if it were the lower temperature.
How Wind Chill Is Calculated
The 2001 NWS/Environment Canada formula models heat loss from a human face moving at walking speed through the wind. Air doesn't get colder when it blows — it strips the thin layer of body-warmed air off your skin faster, so you lose heat at the rate you would in calmer, colder air. That's also why wind chill only affects living things: your car cools to the air temperature faster in wind, but never below it.
Formula (°F, mph)
WC = 35.74 + 0.6215T − 35.75·V^0.16 + 0.4275·T·V^0.16 (valid for T ≤ 50°F and wind ≥ 3 mph) 30°F + 15 mph → 19°F 0°F + 15 mph → −19°F 20°F + 25 mph → 3°F −10°F + 20 mph → −35°F Frostbite on exposed skin: ~30 min at −18°F wind chill, ~10 min at −32°F, ~5 min at −48°F
Frequently Asked Questions
Does wind chill affect cars, pipes, or machinery?
Only the speed of cooling, not the destination. Wind makes objects reach the air temperature faster, but they can never drop below it — a pipe can't freeze at 40°F no matter the wind. Wind chill temperatures describe heat loss from living, heat-generating bodies.
At what wind chill does it become dangerous to be outside?
Around −18°F wind chill, exposed skin can frostbite in 30 minutes — that's the threshold where US wind chill advisories typically begin. At −32°F it drops to about 10 minutes, and at −48°F to 5. Hypothermia risk rises well before frostbite if you're wet or underdressed.
Why did the wind chill formula change in 2001?
The original 1945 Siple-Passel index was based on water freezing in a can on an Antarctic pole, and it badly overstated cooling. The 2001 replacement modeled heat loss from human faces in a wind tunnel at walking speed — today's readings run 10–15°F 'warmer' than the old chart for the same conditions.
Does wind chill apply to dogs and other pets?
Yes — any warm-blooded animal loses heat faster in wind, though fur changes the threshold, not the principle. Short-coated breeds, puppies, and senior dogs need limits similar to humans; even thick-coated breeds lose protection when wind parts the coat or the fur gets wet.