Well the refer experiment worked quite well. I was impatient and the sensor only got down to 41F. Putting it in the sun got a range of 41F - 90F a good range to determine the scaling values.
Pretty pictures:
PSI scaling, input sensor reading is the X axis, output PSI value is Y (vertical).
Temp scaling, input sensor reading is X again, output is Y (Orange line is Celsius, blue is Fahrenheit). Extra credit: Guess where the two lines cross (the temperature)?
(If you are curious of how I got the data--e.g. how did I know the temp--I used the "official" app. Since the sensors are Bluetooth Beacons: Bluetooth Beacons broadcast their data. Thus you can have a phone running the official app displaying the data converted to something readable, and some other device also displaying the raw values.)