This is a great thermometer / hygrometer. Its compact size allows it to be placed anywhere in the house, and not be obtrusive. In spite of its smaller dimensions, it is easy to read: I am 71, and can see the numbers on mine from several feet away. It seems to react to temperature and humidity changes promptly. The ability to view high / low readings for the past 24 hours is surprisingly useful. The hygrometer seems accurate enough, based on comparing it to two other digital thermometer / hygrometers I have. And, its calibration feature has come in very handy - although the thermometer was probably accurate to start with, I tweaked it one degree higher, so it reads the same as the thermometer in the furnace / AC thermostat does. I'm not sure which one is the closest to being totally accurate, but IMHO it's better to have them both be in sync, than to be off by a degree or two. For example, by determining the temperature differential between the thermostat and the bedrooms at the opposite end of the house, I can use that information to figure out what heat setting is required to keep the bedrooms from getting too cold at night. It would be nice if the temperature and humidity readings were switched in position (i.e., temperature in a larger size on the top), but since most other competitive units have the same configuration, I will not ding the AcuRite for it.

Worked great out of the box. A few weeks later, the hygrometer stopped correctly reporting RH below 10%. I'm using this inside a "dry box" containing a heating rod, small fan, and large can of desiccant. The thermometer still works great - displayed temp is within a couple degrees of actual. However, the prolonged exposure to extremely dry conditions appears to have caused the humidity display to fail - it constantly reads >70% RH when inside the box, and when I take it out to check on it, the RH wraps around to 10% and begins to climb normally. The box itself is obviously not up in the 70%+ RH range, because the desiccant still shows good (colored silica beads - they'd turn color within minutes if it were that humid). It appears that the sensor loops from low to high once the RH reaches a certain low threshold for an extended period. Probably fine for use in normal room conditions, but too error-prone for extremes, especially when accuracy is important.

Advertised as having an RH range of 0-99%. In reality it does not go below 10%. When the RH drops below 10%, instead of reading say 9%, it will read 90% and the arrow will be on the red (High RH) line. I think the sensor is accurate, but the firmware was not written correctly. I called customer service at Acurite and they were extremely incompetent. I eventually gave up with them with trying to deal with the issue because they kept passing me around and closing my case without resolving my issue.

I have used this brand of thermometer/hygrometer at my job for about 10 years. They work well and are accurate. Acurite products have proven to be reliable for me. I'm not sure what the difference is between this white model and the standard black/silver model (see photo), perhaps it claims better accuracy, but side-by-side, they have the same readings. Recommended.

I bought two of these, to verify that they were at least accurate between units. I also have several other temp/humidity units that seemed to not match up with their readings.
RESULTS:
The two AcuRite 01083M Pro units were accurate between the two units.The temperature always read the same between the two, and the humidity usually read the same between the two. Sometimes the humidity differed by a percentage point between the two.
The temperature readings matched up accurately with my other thermometers.
The humidity readings matched up closely with one of my other humidity monitors.
CONCLUSION:
The temperature readings and humidity readings are ACCURATE.

It is apparently technically more difficult to get an accurate humidity reading, as you can verify if you read reviews of other humidity monitors. So, I am very pleased with the accuracy of the humidity readings on this monitor. I bought these mainly to get an accurate humidity reading on different levels of my home. So, I am pleased that the main/top reading is of the Humidity %. That is my main interest. I know there have been other reviewers who have complained about the prominence of the humidity reading. But, I suspect that for those who are mostly interested in the humidity reading, this is, in fact, a benefit -- not a detriment.

I know that the unit can be calibrated (that's a big plus, too), but I have not had to re-calibrate my two units.