Wireless Fridge Thermometer - Are they accurate?

I have both Accurite and Lacross. Agreement does not often happen but 1-2 Degrees off is normal.. of course the senders are in different places and that can affect things too. The one in the fridge is a Lacross.. I tried it in the freezer but it ceased transmitting due to cold. I'd use a calibrated dial or liquid type in the freezer Calibration explained above.