Product review (1 stars): Defective with quick temperature rise.
With a quick temperature rise, such as from cloudy to sunny, this adds much more:  Today, the outside temperature is about 49 F, this reads 77 F.  The other devices read from 49 to 55, the 55 item is a thermocouple that close to brick that was is the sun.  Used a infrared sensor on the outside sensor for this device.  It reads 49 F.  O:ne, or both units, the exterior sensor or the readout is defective.  The batteries are new alkaline, tested excellent with a battery tester.  Other consumers have the same problem.  I will ask for refund; this was a Christmas present, and we have had the usual cloudy mostly, here in eastern Missouri.  Reads 76 F, actual with 3 other methods, 49 F