Hi mates,
since I've been asked many time for dew point here is a simple formula to calculate it.
Cause some API or Garmin weather does not provide it, it may help you.
function DewPoint(T,Hr){
Hr = Hr/100.0;
var A = (17.27 * T)/(237.7+T);
A = A + Math.ln(Hr);
var Tr = (237.7 * A) / ( 17.27 - A);
return Tr;
}
Where T = temperature in celcius
Hr = Humidity in %
Heinrich Gustav Magnus-Tetens formula:
fr.wikipedia.org/.../Point_de_rosée
the result is in celcius also.