CFLib.org – Common Function Library Project

Description:
This function calculates the wind chill based upon the new NWS Wind Chill Index calculations. Source: http://www.crh.noaa.gov/dmx/0winter/new_windchill.html According to the documentation, this new cacluation will:

• Use wind speed calculated at 5 feet (average human face height)
• Be based upon a human face model
• Incorporate modern heat flow theory
• Lower the calm wind threshold to 3 mph
• Use a consistant standard for skin tissue resistance
• Assume the worst case for solar radiation (clear night sky)

Return Values:
Returns the wind chill.

Example:

<cfset VARIABLES.intFahrenheit = 35>
<cfset VARIABLES.intWindSpeed = 30>
The Wind Chill is <cfoutput>#CalculateWindChill(VARIABLES.intFahrenheit, VARIABLES.intWindSpeed)#</cfoutput> degrees Fahrenheit.<br>

Parameters:

Full UDF Source:

/**
 * This function calculates the wind chill based upon the new NWS Wind Chill Index calculations.
 * 
 * @param intAirTemperature      Temperature 
 * @param intWindSpeed      Wind speed in MPH 
 * @return Returns the wind chill. 
 * @author Russel Madere (rmadere@turbosquid.com) 
 * @version 1, August 22, 2001 
 */
function CalculateWindChill(intAirTemperature, intWindSpeed)
{

    return Round(35.74 + (0.6215 * intAirTemperature) - (35.75 * (intWindSpeed ^ 0.16)) + (0.4275 * intAirTemperature * (intWindSpeed ^ 0.16)));

}