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Wind Chill Temperature Calculator

Wind chill equals 35.74 plus 0.6215 times T minus 35.75 times V to the 0.16 plus 0.4275 times T times V to the 0.16

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NWS Wind Chill Formula

Wind chill measures how cold it feels when wind accelerates heat loss from exposed skin. The NWS/Environment Canada formula (revised 2001) takes air temperature in °F and wind speed in mph to produce a single “feels like” temperature.

WCT = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16

How It Works

Wind chill measures how cold it feels when wind accelerates heat loss from exposed skin. The NWS/Environment Canada formula (revised 2001) takes air temperature in °F and wind speed in mph to produce a single “feels like” temperature. Wind removes the thin layer of warm air next to your skin much faster than still air.

Example Problem

The air temperature is 5°F and the wind speed is 30 mph. What is the wind chill?

  1. V^0.16 = 30^0.16 ≈ 1.738
  2. WCT = 35.74 + 0.6215(5) − 35.75(1.738) + 0.4275(5)(1.738)
  3. WCT ≈ 35.74 + 3.11 − 62.13 + 3.71 = −19.6°F

At this wind chill, frostbite can develop on exposed skin in about 10–30 minutes.

When to Use Each Variable

  • Solve for Wind Chill — when you know the air temperature and wind speed, e.g., determining how cold it feels before going outdoors in winter.
  • Solve for Air Temperature — when you know the wind chill and wind speed, e.g., finding what actual air temperature corresponds to a reported wind chill value.
  • Solve for Wind Speed — when you know the air temperature and wind chill, e.g., determining what wind speed is causing a specific feels-like temperature.

Key Concepts

Wind chill quantifies the enhanced rate of heat loss from exposed skin caused by wind. The NWS formula (revised 2001) was derived from human trials measuring facial skin cooling rates at various temperature and wind combinations. It assumes a walking speed of 3 mph, 5-foot height, nighttime conditions, and no solar radiation heating.

Applications

  • Weather forecasting: issuing wind chill advisories and warnings to protect public safety
  • Outdoor work safety: determining exposure time limits for construction, utility, and military personnel
  • Winter sports planning: assessing frostbite risk for skiing, snowboarding, and mountaineering activities
  • Emergency management: evaluating hypothermia risk during cold-weather evacuations and power outages

Common Mistakes

  • Applying wind chill to inanimate objects — wind chill only affects warm-blooded organisms; a car engine cannot cool below the actual air temperature from wind alone
  • Using the formula above 50 degrees F or below 3 mph wind — the NWS equation is not valid outside these bounds and produces meaningless results
  • Confusing wind chill with actual temperature for pipe-freezing risk — pipes freeze based on actual air temperature, not wind chill
  • Ignoring wind chill when layering clothing — exposed skin at -20 degrees F wind chill can develop frostbite in under 30 minutes even if the actual temperature is only 5 degrees F

Frequently Asked Questions

How does wind chill work?

Wind increases the rate at which your body loses heat by stripping away the warm boundary layer of air on your skin. The wind chill formula quantifies this effect as an equivalent calm-air temperature that would produce the same heat loss rate.

At what wind chill does frostbite happen?

At wind chill values between 0°F and −10°F, frostbite can occur within 30 minutes. Below −25°F, it can happen in 10–15 minutes. Below −45°F, frostbite is possible in under 5 minutes on any exposed skin.

Does wind chill affect pipes or car engines?

No. Wind chill applies only to living organisms that generate heat. An inanimate object will cool faster in wind, but it will not drop below the actual air temperature. A car radiator at 20°F will not freeze from wind chill alone.

What is the wind chill formula valid range?

The NWS equation is valid for air temperatures at or below 50°F and wind speeds above 3 mph. At higher temperatures the formula is not meaningful because wind actually helps cool the body through evaporation and feels comfortable.

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