# CFLib.org – Common Function Library Project

## CalculateWindChill(intAirTemperature, intWindSpeed)

##### Last updated August 22, 2001

Version: 1 | Requires: CF5 | Library: ScienceLib

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

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:

Name Description Required
intAirTemperature Temperature Yes
intWindSpeed Wind speed in MPH Yes

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.
* @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)));

}``````

date2ExcelDate
May 5, 2016

CapFirst
April 25, 2016