AT = Ta + 0.33•ρ − 0.70•ws − 4.00
ρ = rh • 6.105 • e(17.27*Ta/(237.7+Ta))
- AT is the Apparent Temperature in oC;
- Ta is the Dry bulb Temperature in oC;
- ρ is the water vapor pressure (hPa);
- ws is the wind speed (m/s) at 10 meter above the ground;
- rh is the Relative Humidity (%).
Reference here: http://www.bom.gov.au/info/thermal_stress/#atapproximation and there’s a simple calculator here: https://www.vcalc.com/wiki/rklarsen/Australian+Apparent+Temperature+(AT)