Weather Calculations

Weather Calculations

Heat Index Calculation

Enter in the air temperature ( Tair ) in degrees Fahrenheit and relative humidity ( RH ) in percent ( without the % sign ), then click on the Calculate HI to compute the heat index ( HI ).

Relative Humidity Calculation

Enter in the air temperature ( Tair ) and dew point temperature ( Tdp) in degrees Fahrenheit ( oF ) then click on the Calculate RH to compute relative humidity( RH ).

Here is the formula to calculate the Wind Chill:

T(wc)=.081 x (3.71 x sqrt(V) + 5.81 – 0.25 x V) x (T – 91.4) + 91.4 , where T(wc) is the Wind Chill in degrees F, V is the Wind Speed in MPH, and T is the temperature in degrees F. You can use the calculator below which uses this formula.