Barometric pressure needs to be adjusted for station elevation. I am at about 175' above MSL. Local airport about 2 miles away shows pressure at 30.06 mmHg, but I can only calibrate mine +0.1 mmHg upward giving a reading of 29.87. A little wider adjustment range would be nice. Certainly not a professional weather station but it is what it is. Guess the trend is more what you are interested in.