Outside temp stays at 75F although it is over 90F…Never changes
I think this is what you are asking about.
How To Replace Or Reset Ambient Temperature Sensor - CAR FROM JAPAN
Outside temperature displays are slow to update, it generally takes a few consistent miles at 45 MPH or greater for the display to begin to update. The reason for this is at lower speeds the ambient temperature sensor is greatly influenced by the heat from the radiator/A/C condenser and road surface heat.
Do you live in Philadelphia?