We just purchased an Acurite Weather Station 02074. We have the outside weather sensor lying flat on the shelf over our Front door. Is laying flat ok or should it be upright. Also when I had outside sensor in the house it registered the same temperature inside an out. Before I layed it flat I had it on a plant stand and temp. seemed OK, But when I put it on the shelf flat it is registering about 6 degrees different than what the weather channel says? Think it is too sheltered?