Product review (2 stars): Inaccurate readings
First off, I purchased this item so I could know the humidity, otherwise, I would have bought another model.  I don't know how accurate the indoor readings are, but I do know the outdoor readings are far off.

With the outside temp running around 100 degrees, it has showed outdoor humidity of 1% throughout most of the afternoon, two days in a row.  At night it climbed to 24%, which might be accurate.

Obviously the humidity isn't 1% outside.  It is around 7 to 10%.  I wanted to know the humidity levels because I use evaporative cooling in Arizona, and it really affects the performance of the cooler.  This item is worthless for me, other than keeping track of the temperatures.