Wind Chill Calculator

Calculate the "feels like" temperature based on actual air temperature and wind speed using the National Weather Service formula.

Quick Facts

Formula Valid Range
-50F to 50F
Wind speed 3+ mph
Frostbite Risk
-18F or below
Can occur in 30 min
NWS Formula
Since 2001
Updated from 1945 version
Key Factor
Heat loss rate
From exposed skin

Your Results

Calculated
Wind Chill
0F
Feels like temperature
Actual Temperature
0F
Air temperature
Difference
0F
Cooling effect

Low Risk

Conditions are relatively comfortable.

Key Takeaways

  • Wind chill measures how cold it feels on exposed skin, not actual temperature
  • The formula is valid for temperatures between -50F and 50F with wind speeds above 3 mph
  • Frostbite can occur in as little as 30 minutes when wind chill drops below -18F
  • Wind accelerates heat loss from your body, making cold weather more dangerous
  • Dress in layers and cover exposed skin when wind chill is low

What is Wind Chill?

Wind chill is a measure of the perceived decrease in air temperature due to the cooling effect of the wind on exposed skin. In simpler terms, it is the temperature that a person would feel on their skin, taking into account the combined effect of the actual air temperature and the wind speed. The wind chill temperature is always lower than the actual air temperature, and the difference between the two increases as wind speed increases.

The concept of wind chill was first introduced by Paul Siple and Charles Passel, two Antarctic explorers who conducted experiments to understand the relationship between wind speed and the rate of heat loss from the human body. Their research laid the foundation for the development of wind chill indices, which are now used by meteorologists and weather forecasters to provide more accurate information about how cold it feels outside.

The Wind Chill Formula

Wind chill is calculated using a formula that takes into account the actual air temperature and wind speed. The most widely accepted formula today is the National Weather Service's Wind Chill Index:

Wind Chill (F) = 35.74 + 0.6215T - 35.75V0.16 + 0.4275TV0.16
T = Air Temperature (F)
V = Wind Speed (mph)

This formula provides an estimation of the wind chill temperature in Fahrenheit for air temperatures between -50F and 50F and wind speeds between 3 mph and 110 mph. For temperatures outside this range or wind speeds lower than 3 mph, the wind chill effect is considered negligible.

Example Calculation

Let's say the air temperature is 10F, and the wind speed is 15 mph. Using the formula above:

Wind Chill (F) = 35.74 + 0.6215 x 10 - 35.75 x 150.16 + 0.4275 x 10 x 150.16

After performing the calculations, we find that the wind chill temperature is approximately -4F. This means that although the actual air temperature is 10F, the cooling effect of the wind makes it feel like -4F on exposed skin.

Frostbite Warning

When wind chill drops below -18F, frostbite can occur on exposed skin in as little as 30 minutes. At -40F wind chill, frostbite can happen in just 10 minutes. Always cover exposed skin and limit outdoor exposure in extreme cold.

Wind Chill and Safety

Wind chill plays a crucial role in meteorology and weather forecasting. Accurate weather predictions help people plan their day, dress appropriately for the weather, and take necessary precautions to stay safe in extreme conditions.

This information is particularly important in regions that experience harsh winter conditions, as it helps individuals and organizations make informed decisions about school closures, road maintenance, and emergency services. Understanding wind chill also aids in raising public awareness about the risks associated with cold weather, such as frostbite and hypothermia.

Practical Applications

  • Dressing for the Weather: Knowing the wind chill temperature can help you decide how to dress when going outside in cold weather. Dressing in layers, wearing a hat and gloves, and covering exposed skin can significantly reduce the risk of frostbite and hypothermia.
  • Outdoor Activities: Understanding wind chill can help you determine the best time for outdoor activities, such as running or skiing. Planning your activities during periods of low wind speeds can make the experience more enjoyable and reduce the risk of cold-related injuries.
  • Travel Planning: When planning a trip to a cold region, knowing the wind chill temperatures can help you pack appropriate clothing and gear to stay warm and safe.
  • Home Maintenance: Homeowners in cold climates may use wind chill information to decide when to perform maintenance tasks, such as clearing snow from driveways and sidewalks or adding insulation to prevent pipes from freezing.
  • Agriculture and Livestock: Farmers and ranchers may use wind chill data to protect crops and livestock from cold weather conditions, such as by providing shelter or additional heating to keep animals warm.

Conclusion

Wind chill is an essential factor in understanding how cold it feels outside, as it takes into account both the air temperature and wind speed. The calculation of wind chill is crucial in meteorology for accurate weather forecasting and in everyday life for making informed decisions about dressing appropriately, planning outdoor activities, and staying safe in cold weather conditions. By understanding the concept of wind chill and its practical applications, we can better prepare for and adapt to the challenges posed by cold weather.