I'm not sure either outside thermometer is correct, but, one showed 27° F and the other showed 33° F when I checked about 8:30 AM. We usually don't see below freezing too often during the Winter. I forgot about the sprinklers and they came on. That means none of the above ground water piping was damaged overnight. I'm sure this River Birch tree was thinking, "WTF. I'm cold anyway and you're hosing me down?"