Sister and Bone Doctor gave me this weather station thing for christmas. We had the outdoor sender unit sitting in a pot plant and in the morning sun, the temperature readings were very high. Finally we bought some double sided tape and so far as I could see, this was the best position. There isn't any air flow from this vent, it is out of direct sunlight, protected from rain and away from the aircon unit blowing hot or cold air out.
The outdoor unit sends an update signal to the unit on the desk about every thirty seconds. Time, date, moon phase, pictorial forecast, indoor temp and humidity and outdoor temp. It does other stuff too, which I can't be bothered to learn. Hmm, why no barometric pressure reading?