Pairing your Garmin wearable device with a tempe external temperature sensor would be one way, I'd imagine.
I do not need a tempe or so. But I would like to know the temperature at my different workouts. I also have a Forerunner 220. As this has no built in temperature sensor I there instead see the temperature and weather from the source EKVD in Garmin Connect. I would like to have this information as the sensor is not trustworthy.