333194fc_Cumulus_ini___CumulusWiki__Function
[Parameter Line Entry] DisplayHumidex=0 [Function] 
Set in the Display Configuration Screen General block 0 = Disabled (default) Heat_index displayed on main screen. The heat index is calculated only if the actual temperature in the shade (not in direct sunlight) is above 27 °C (80 °F), so normal temperature shown here for cooler temperatures. 1 = Enabled, calculated Humidex value to be displayed on the main screen instead of Heat Index. (Note that Cumulus displays degrees C or F for Humidex, whereas strictly speaking it is unitless. This is for the convenience of those who use Fahrenheit but would still prefer to see Humidex displayed, where it might be confusing to show the unconverted value.)
Cumulus.ini - CumulusWiki
Function