My 960's out side temp sensor varies wildly at times. 8 degree out side and the car is running and parked showing 35 degrees C on the dash. I know the book says the temp will vary as the general engine bay heats up etc. Is this normal,

such a vast difference. Car running temp is completely normal. Does any other system take data from this sensor because if it does its going to get some wrong readings.

 

That sensor is mounted down low in front of the radiator, The sensor can easily come loose and touch the ac condenser picking up heat from that.