First I checked it indoors and it gave the same reading as two other indoor thermometers so I assume it's accurate. Then I set about trying it in various locations. I'm in an apartment and have two windows plus a sliding glass door to a roofed balcony. I knew to not put it where sunlight would hit it. I would try it in one location then compare what it said to what NOAA said the temp was for my neighborhood. If the difference was huge then I'd try another location. Finally I found a spot where it's reading closely matches the NOAA reading. It's really a cool thing, just walking up to something so easy to see and finding out how hot or cold or perfect it is outside. Not a necessity of course, just something fun.

Update: For anyone who is having a problem with adhesion, follow the install instructions exactly. You really do need a moist surface and then go around the plastic with a clean cloth to press out the air bubbles to insure it stays put. My original thermometer had gotten unnoticeable dirt between the plastic and the window, causing the top of the plastic to fold over. I wiped it clean with Windex and now I have two that work. Will put the second on a window on the other side of the house. Duhh!Original: Worked great attached to a protected window on the north side of my house. Then, the top of the static cling plastic folded over, making it difficult to read. For the money, good purchase and will get another.

I had this same one for years and needed to replace it. I did not hesitate to go with the same one. Large easy to read, clings well to the glass.UPDATE: Well I hate to report that during that hard freeze we all had that the hand on the thermometer froze up and I wasn't able to calibrate it. I really hate it I really like this thermometer a lot.

**** Preface****After about a year of satisfying performance, I hired some window washing help to do my outside cleaning and forgot to tell them to watch out for the thermometer... Needless to say, it got knocked off by a big brush and destroyed. I ordered another and put it in the same place, but this one didn't stick very well and (it turned out) didn't report sensible or accurate readings. Sometimes it would be right on the money and other times it would be ten degrees off. I couldn't calibrate it because it was inconsistent. I think there must have been something in the works that was rubbing or something because it wouldn't go very far below 60º. I rate the first unit I had at 5 stars and the second at 1 star, so the average is 3. No I won't gamble on another one and I'm sorry if my original review caused some people to buy some bad ones. I will leave the original review in place, however, because it has lots of good info about outdoor thermometer placement and other issues.Original Review:1. Ships in one of the impossible to open, sealed plastic boxes, which seemed inappropriate for such a fragile piece of gear, but I guess it protects the unit "until people try opening it by ripping, stabbing or whatever". I did manage to remove it in one piece and the temp shown was 69º just like in the picture. I didn't worry about that because that's the temp I keep my house in winter, so it could have been accurate.2. Windexed the upper corner of a living room window (outside) and made sure it was clean and dry. Peeled off the unit from the container and carefully placed it so it was not crooked, smoothed out the bubbles, went inside and smiled because it looked great... it's actually bigger than you would expect. I waited an hour and it still read 69º, so I wondered if I got one of the worthless units so many complained about... so I went to the computer and checked Weather Underground, which told me it was indeed 69º outside. Later that night the computer said it was 60 outside, so I checked the new thermometer and guess what! 60º is what it read!3. My main worries are whether it will stay there over time, and how I can wash the outside of the window without ruining it. I did not have to calibrate with the white knob on the back, but it looks easy enough if yours is a little off.I like that it has temp in both C and F, since my wife is a foreigner and still learning about our stupid F scale. I think USA is the last holdout on that archaic measuring system.PLACEMENT is very important for accuracy. Put it in a place where direct sun never hits it, but that the air around it ventilates it well. Do not put it on a large pane of glass that gets hot with the sun... that could be many of the reviewers' problem. Also it's good to be sure the rain is not likely to hit it, because the "works" are protected by a plastic box that has holes in it for air movement. I put mine at the top corner of the window as close under the protective eve of the house as possible, and on a side where the morning and evening sun don't shine on that window. Maybe you don't have such a window to place it in, best to think of that before ordering it and complaining.All in all, I could not be more pleased with the nice thermometer I got for just a few dollars. I had one of the big mechanical wall thermometers that fell just a week after buying it, also had wired and wireless digital units that only lasted a short time or were just a pain to make work... I'm a happy customer! No wires or batteries, cheap enough to replace each year and still come out ahead of the digital cost... great product so far.UPDATE after one month: Don't worry, all is still good, looks great and still always right on the money. The thought hit me just now that I'm telling people to put the thing in the top corner of their window so the sun is less likely to hit it and cause erroneous readings, and that I'm probably one of the few people who does not have curtains that block that area of the window... good luck on your decision of where to put it :) I just don't have curtains because I have a nice view out of those particular windows and it's away from the sunshine.7 MONTH UPDATE: I was spraying the windows today in preparation to wash them and suddenly realized I was spraying (pressure stream) right onto the Thermometer. After cursing my stupidity, I went inside to check and it still seemed OK, and later in the day it was still reading accurately. Maybe I was over-protective... so that's a good thing. Still recommended.

I used to have those white, round exterior thermometers, that require to be hanging on a nail somewhere. And preferably somewhere near a window, so that I could see what the temperature is when I want it, without having to run out to get the information. While the ones I bought were usually big enough, they would often fall down when a big gush of wind tossed them off the wall or post. Sunlight, cold and rain also make the polymers brittle over time, well... there just does not seem to be the perfect one!I found this novel item: a thermometer combined with a dial that is flat and clingy. I installed easily it on the outside of the window right next to my back yard door. Just clean the pane, and for good measure, I scraped it with a scraping blade (the flat side of it, mind you - before anybody gets into some quirky comments!) After that, just flatten the thing to the still moist pane, rub it to chase the air out to the edges, dry it off with a soft cloth, and - bingo!And here is where things turn to the dark side:This was my plan of how to use this thermometer:Every morning before leaving, the temperature info would be right at my height, and eye sight, on the window.It would be fun and also pretty to look at, almost artsy! The other thing I loved about it is that it shows the values in degrees F and C, which might be a great way to teach kids about the fact that in other countries, people use a different measuring unit.HOWEVER!!! It just does NOT work. Yes, there is a so-called calibration screw on it, but... even that does not set things right. It has been on my window since this morning, and I have monitored it with the help of another outdoor thermometer. This thing, while pretty, is not doing its job. It is simply off the chart, in any direction one can think of. How disappointing! Some people here said that they left it outside for some days and eventually, it sorted itself out. Well, no... I don't think so. A measuring instrument that is based on physical properties and conditions either works right away or not at all. This one hits the spot at "not at all".I called Amazon Customer Service, explained my disappointment, and they are sending me a return label as I am typing this, and as soon as I print it out, it will be on its way back there!One more thing:It won't reveal its country of origin anywhere, not on the packaging nor on the item itself, but here is my strong guess: "Made in China".... once more! This coming from somebody who loves being in China and spends lots of time there! Please, China, stop making crApowski stuff! We are tired of all that junk! Start shipping only products that can actually pass the quality control and if possible with a "pass" rate superior to 90 %. That would be a start!