Routine comparing outside humidex versus Nest thermostat humidex

[LModena]

Hi,

I'd like to create an automation like so:

IF (outside humidex) < (inside humidex)

THAN switch on an exhaust fan.

* Outside humidex is public information on the internet 

* Inside humidex can be calculated based on the Nest thermostat sensors

Is this function in Google Home's roadmap?