I am seeking assistance on the best placement of the outside sensor that controls my heat pump/gas furnace. My hvac system is sold under the name of Goodman and it uses the Honeywell vision pro thermostat.

My concerns over the outsider sensor is that the readings of outside temperature deviate by 5 - 8 degrees from the actual outside temperature. I noticed that when it rains, the temperature deviation is even more. For example, the other day when it rained, the actual outside temperature was 42 degrees; the reading on the thermostat said that the outside temperature was 11 - 21 degrees . . . Wierd!

I'm wondering if the placement of the outside should be in a sheltered place. Any assistance on this matter will be greatly appreciated.

Thank you in advance.