I actually own a Tempe sensor that I used years ago with an old vivoactive that had no temp sensor but the Tempe is such a dumb useless sensor (and way overpriced) that I never use it with the Fenix and just adjust for the internal temp sensor.
But the Fenix doesn't use that internal temp sensor for anything serious, just barometer adjustments internally.
However it dawns on me to ask if by any chance the firstbeat metrics would use the Tempe as a trusted temperature source instead of the forecast?
My guess is "no" as with everything remotely complicated vs Garmin but hoping otherwise?
That forecast data is so freaking useless. Garmin needs to let people use their own personal weather stations instead if they have one.
I have to force the zip code like 200 miles south to get the real temperature/humidity.
BTW Garmin, the sensors list on the apps say the Tempe battery is "ok" but the Tempe is such a dumb old sensor it doesn't support battery status.
Unless there is a newer firmware version of the Tempe but even that cannot be updated, it's literally the dumbest Garmin sensor, doesn't even have humidity or barometer.