I have the same problem. Mine reads +2 degrees higher when in direct sunlight and -2 degrees lower for the early morning low, but seems accurate on overcast days when there's a breeze. Calibration is useless because of the above variances. Mine is mounted on a 10ft pole in the only usable location I have, so I can't move it.
I'm interested in what you do, please report back on any of your adjustments.
I'm interested in what you do, please report back on any of your adjustments.