Wind Chill Calculator

Calculate how cold it feels based on temperature and wind speed

❄️ Wind Chill Calculator

Calculate how cold it feels on exposed skin by combining air temperature and wind speed

What is Wind Chill?

Wind chill is a measure of how cold it feels on exposed skin when the effects of temperature and wind speed are combined. It quantifies the rate of heat loss from the human body in cold, windy conditions.

The wind chill temperature is always lower than the actual air temperature (except when there is no wind). This is because wind increases the rate at which moisture evaporates from the skin and heat is carried away from the body, making you feel colder than the actual air temperature.

Understanding wind chill is crucial for outdoor safety, as it helps estimate the risk of frostbite and hypothermia. The National Weather Service uses the wind chill index to issue cold weather advisories and warnings to protect public health.

How to Use This Calculator

Enter the wind speed in your preferred unit (mph, km/h, m/s, or knots)
Enter the air temperature in your preferred unit (°F, °C, or K)
Click 'Calculate Wind Chill' to see the results
Review the wind chill temperature and safety recommendations
Use the 'Clear' button to reset and perform another calculation

Latest Insights & Guidelines

The current wind chill formula used by the National Weather Service and Environment Canada was developed in the early 2000s using advanced heat-transfer modeling and human-subject experiments. It provides a more accurate representation of how cold conditions feel on exposed skin compared to older formulas.

Key points about wind chill:

Wind chill is only defined for temperatures at or below 50°F (10°C) and wind speeds above 3 mph (4.8 km/h)
The formula assumes typical winter conditions: clear night sky, no sun, and wind measured at face level (about 5 feet above ground)
Wind chill applies to exposed human or animal skin, not inanimate objects - water will not freeze faster due to wind chill if the air temperature is above freezing
Individual factors like body size, clothing, humidity, sun exposure, and activity level can affect how cold you actually feel

For warm or humid conditions, other indices like the heat index or apparent temperature are more appropriate measures of thermal comfort.

Understanding Wind Chill Calculation

The Wind Chill Formula

The North American wind chill formula (in Fahrenheit and mph) is:

T_wc = 35.74 + 0.6215T_a - 35.75V^0.16 + 0.4275T_aV^0.16

The metric version (Environment Canada) uses Celsius and km/h:

T_wc = 13.12 + 0.6215T_a - 11.37V^0.16 + 0.3965T_aV^0.16

When is Wind Chill Valid?

Wind chill calculations are only valid under specific conditions:

Temperature must be at or below 50°F (10°C)
Wind speed must be greater than 3 mph (4.8 km/h)

Health Risks and Safety

Wind chill helps estimate the risk of cold-related health issues:

Wind chill above 32°F (0°C): Relatively safe with proper clothing
Wind chill 15°F to 32°F (-9°C to 0°C): Increased risk of hypothermia with prolonged exposure
Wind chill -15°F to 15°F (-26°C to -9°C): Significant risk of frostbite and hypothermia; limit outdoor exposure
Wind chill below -15°F (-26°C): Dangerous conditions; frostbite possible in 30 minutes or less

Frequently Asked Questions

Why does wind make it feel colder?

Wind removes the thin layer of warm air that surrounds your body, increasing the rate of heat loss. This makes the temperature feel colder than it actually is, even though the air temperature hasn't changed.

Can wind chill freeze water faster?

No. Wind chill only affects living organisms with body heat. Water or other objects will not freeze faster due to wind chill if the air temperature is above freezing. However, wind can speed up evaporative cooling.

Is wind chill the same as 'feels like' temperature?

Wind chill is one component of 'feels like' or apparent temperature. In cold conditions, wind chill is used. In warm conditions, the heat index (which accounts for humidity) is used instead.

How accurate is the wind chill formula?

The current formula is based on scientific research and provides a good estimate for typical conditions. However, individual perception can vary based on clothing, activity level, body composition, and other factors.

At what wind chill should I stay indoors?

When wind chill drops below -15°F (-26°C), there is significant risk of frostbite within 30 minutes. Below -50°F (-45°C) is considered extremely dangerous. Always follow local weather service warnings and advisories.

Does wind chill affect my car or home?

Wind chill does not directly affect inanimate objects like cars or buildings. However, wind can increase heat loss from buildings and affect heating costs. Your car's engine will not get colder than the actual air temperature due to wind chill.