How is Windchill Calculated

by

Wind Chill Calculator

Enter the air temperature in Fahrenheit and the wind speed in miles per hour to calculate the wind chill temperature.

function calculateWindChill() { var airTemperatureInput = document.getElementById("airTemperature").value; var windSpeedInput = document.getElementById("windSpeed").value; var resultDiv = document.getElementById("windChillResult"); var errorDiv = document.getElementById("windChillError"); resultDiv.innerHTML = ""; // Clear previous result errorDiv.innerHTML = ""; // Clear previous error var airTempF = parseFloat(airTemperatureInput); var windSpeedMph = parseFloat(windSpeedInput); if (isNaN(airTempF) || isNaN(windSpeedMph)) { errorDiv.innerHTML = "Please enter valid numbers for both air temperature and wind speed."; return; } var windChillF; // Wind Chill Formula (NWS/Environment Canada) is valid for Ta 3 mph if (airTempF > 50 || windSpeedMph 50°F or Wind Speed <= 3 mph), the wind chill is considered to be the same as the air temperature: " + windChillF.toFixed(1) + "°F"; } else { // Twc = 35.74 + 0.6215Ta – 35.75(V^0.16) + 0.4275Ta(V^0.16) windChillF = 35.74 + (0.6215 * airTempF) – (35.75 * Math.pow(windSpeedMph, 0.16)) + (0.4275 * airTempF * Math.pow(windSpeedMph, 0.16)); resultDiv.innerHTML = "The calculated Wind Chill Temperature is: " + windChillF.toFixed(1) + "°F"; } }

Understanding Wind Chill: How Cold Does It Really Feel?

Wind chill is a term used to describe how cold it feels outside to the human body, taking into account both the actual air temperature and the wind speed. It's not the actual temperature of an object, but rather a measure of the rate of heat loss from exposed skin due to the combined effect of cold air and wind.

Why is Wind Chill Important?

Understanding wind chill is crucial for safety during cold weather. A low wind chill temperature indicates a higher risk of frostbite and hypothermia, even if the actual air temperature isn't extremely low. The faster the wind blows, the more quickly your body loses heat, making it feel much colder than the thermometer indicates. This knowledge helps individuals dress appropriately, limit outdoor exposure, and take necessary precautions to prevent cold-related injuries.

How is Wind Chill Calculated?

The standard formula for calculating wind chill, adopted by the U.S. National Weather Service and Environment Canada, is based on a scientific model that measures the rate of heat loss from a human face. The formula is:

Twc = 35.74 + 0.6215Ta - 35.75(V^0.16) + 0.4275Ta(V^0.16)

Where:

  • Twc = Wind Chill Temperature (in Fahrenheit)
  • Ta = Air Temperature (in Fahrenheit)
  • V = Wind Speed (in miles per hour)

Important Conditions for the Formula:

This formula is specifically designed for conditions where the wind chill effect is significant. It is valid only when:

  • The air temperature (Ta) is 50°F (10°C) or below.
  • The wind speed (V) is above 3 mph (4.8 km/h).

If the air temperature is above 50°F, or if the wind speed is 3 mph or less, the wind chill temperature is generally considered to be the same as the actual air temperature. In these cases, the wind's cooling effect on exposed skin is minimal or negligible.

Using the Wind Chill Calculator

Our Wind Chill Calculator makes it easy to determine the "feels like" temperature. Simply input:

  1. Air Temperature (°F): The current temperature of the air in Fahrenheit.
  2. Wind Speed (mph): The speed of the wind in miles per hour.

Click "Calculate Wind Chill," and the calculator will instantly provide the wind chill temperature, helping you understand the true impact of the weather conditions.

Examples of Wind Chill Calculation:

  • Example 1: If the air temperature is 20°F and the wind speed is 15 mph, the wind chill temperature would be approximately 4.0°F. This means it feels like 4.0°F on exposed skin.
  • Example 2: With an air temperature of 0°F and a wind speed of 10 mph, the wind chill drops significantly to about -16.0°F.
  • Example 3: If the air temperature is 40°F and the wind speed is 5 mph, the wind chill is approximately 34.0°F.
  • Example 4 (Edge Case): If the air temperature is 60°F and the wind speed is 10 mph, the wind chill is considered to be 60.0°F (same as air temperature) because the air temperature is above 50°F.
  • Example 5 (Edge Case): If the air temperature is 10°F and the wind speed is 2 mph, the wind chill is considered to be 10.0°F (same as air temperature) because the wind speed is 3 mph or less.

Always be mindful of wind chill when planning outdoor activities in cold weather to ensure your safety and comfort.

Leave a Comment