Outside temperature Prius 2017

It'll never be accurate - it takes the temperature of where it's located. Not sure about where it is on PRIUS - my last car was behind the front bumper cover quite low toward one side..

• If it's been parked under a tree, it's quite accurate - sort-of.
• If it's been driven and just parked on a hot surface - tends to read high, I suspect, because of radiant heat from the road.
• Parked in the sun - gives a reasonable idea - but I wouldn't say accurate.
• Parked in an underground carpark - reasonably accurate - but bear in mind radiant heat from engine/radiator will make it read high if it's only just been parked.

I think it's more for entertainment purposes "guess what the real temperature is".

Maybe tow one of these Stephenson's Screens - which comes with quite prescriptive instructions on installation.

 

On our 2016 Prius v Three the sensor is located under the front bumper...

 

Found it:


It's listed in among the components of the AirConditioner Neural Network Control.

The A/C uses it, as well as other sensors etc to run the A/C:

 

THIS is all you need to know.
Not worth your time, money or trouble to try and make it more accurate.
That would be a losing proposition.

 

Same place as the Gen 3 then (OP has 2012 in his sig).