About this Wind Chill
When the wind blows, it strips away the thin layer of warm air trapped near your skin, making you feel colder than the thermometer indicates. This 'Wind Chill' factor is critical for safety in winter conditions, as it drastically reduces the time it takes to get frostbite.
Who this calculator is for
- People heading outside in cold, windy weather.
- Outdoor workers, runners, and winter travelers checking exposure risk.
- Parents and drivers planning how long people can safely stay outside.
When to use it
- Check the apparent temperature before going outside.
- Estimate frostbite risk during winter travel or outdoor work.
- Decide whether extra layers or a shorter exposure window are needed.
How to use this calculator
- Enter the outside Air Temperature.
- Enter the Wind Speed.
- The result is the Wind Chill ('Feels Like') temperature.
Key assumptions
- The formula only applies at 50°F or below and winds above 3 mph.
- The result is for exposed skin and does not include sun or precipitation effects.
- This calculator uses the standard NWS wind chill equation.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
The calculator uses the official National Weather Service (NWS) formula adopted in 2001:
`Wind Chill = 35.74 + (0.6215 × T) - (35.75 × V^0.16) + (0.4275 × T × V^0.16)`
* T: Air Temperature (°F)
* V: Wind Speed (mph)
Note: Wind chill is only defined for temperatures at or below 50°F and wind speeds above 3 mph.
Inputs explained
Air Temperature
The temperature read from a thermometer. Must be 50°F (10°C) or lower.
Wind Speed
The sustained wind speed. Gusts can make it feel even colder momentarily.
Understanding your results
The result is the effective temperature on exposed skin.
* 0°F to -19°F: Frostbite possible in 30 minutes.
* -20°F to -39°F: Frostbite possible in 10 minutes.
* -40°F to -59°F: Frostbite possible in 5 minutes.
Example scenarios
Breezy Day
Temp 30°F, Wind 15 mph. Feels like 19°F.
Blizzard
Temp 0°F, Wind 25 mph. Feels like -24°F (Frostbite risk in < 30 min).
Key Features
- NWS Formula
- Frostbite Awareness
- Instant Calculation
Tips & Best Practices
- Wind chill only affects living things (humans/animals). It does not freeze water pipes faster (pipes only care about the actual air temp), but it does cool them down to ambient temp faster.
- Dress in layers and cover exposed skin to mitigate wind chill.
Glossary of Terms
- Frostbite
- Damage to skin and tissue caused by extreme cold.
- Hypothermia
- A dangerous drop in body temperature caused by prolonged exposure to cold.