Product review (5 stars): An excellent and affordable handheld weather meter
I've been using my WM-3 for a few weeks now and I've been quite impressed with the accuracy of this meter.  The readings were nearly spot on with my full sized calibrated weather station.

The unit itself is compact and very lightweight, it almost seems too light, I weighed it at a mere 51 grams, but it doesn't come across as cheap feeling in the slightest.  It's constructed out of a sturdy plastic, nothing bends or creaks and the buttons have a nice positive click to them.  This thing is solidly put together.

Its small size allows it to fit easily in a pocket or tossed in a bag, it also comes with a nice protective case and lanyard, and the light weight allows it to basically be forgotten about until needed.

Actual operation of the unit could not be easier.  One button and it's alive and taking measurements.  A backlight automatically illuminates for 10 seconds, so even in the dark, it's really easy to operate.  Switching between the various modes and units of measurements is easily accomplished with two other buttons.

I'm not a professional by any means, but I do consider myself to be a weather buff.  The unit allows for calibration, but honestly, unless you have a calibrated reference source to adjust it again or have some need for extremely precise measurements, it's best left alone and is going to be more than accurate enough right out of the box.  Remember, this is a $29 instrument, but even still, I was very impressed with its accuracy.

This is a great gadget and especially so for anyone that spends a lot of time outdoors such as hikers or hunters or boaters, pilots, professional weather spotters or just general weather nerds, or just people who like gadgets.

I suppose if I had one gripe, I would have loved to see this unit do pressure too, but at this price point, that's asking a bit much, and Ambient Weather has an excellent range of higher end handheld weather stations that can perform all sorts of neat additional functions.  For the asking price though, the WM-3 is a fantastic value.