Quick verdict
A backlit thermometer and hygrometer that logs temperature and humidity every ten seconds, stores two years of data and sends it by Bluetooth to a phone app up to 260 feet away in the open. Stated accuracy is 0.9 F and 2 percent relative humidity, the app needs no account, and data exports for your own charts. For a greenhouse, it answers the question a glance never can: how cold did it really get at 4 a.m.
Strengths
- Logs and stores two years of temperature and humidity data
- Bluetooth to phone up to 260 feet unobstructed
- Stated accuracy 0.9 F and 2 percent RH, 10 second refresh
- Large backlit display with comfort indicator
- App works without registration and exports data
Weaknesses
- Bluetooth only; no remote access away from home
- Range through walls is far less than 260 feet
- No outputs to control heaters or fans
The overall YardToolLab Score is out of 100. Section scores are out of 10.
Knowing What Happened Overnight
A greenhouse thermometer tells you the temperature now. What kills plants is the temperature at 4 a.m., and the only way to know that is a log. TempPro’s TempAir records temperature and humidity every ten seconds, keeps two years of history and sends it over Bluetooth to a phone app up to 260 feet away in the open. The maker states accuracy of 0.9 F and 2 percent relative humidity, the display is large and backlit, and the app requires no account.
This review is based on the maker’s specifications and on how Bluetooth logging hygrometers perform in greenhouses generally. We have not run this unit ourselves.
Logging
The value is in the history. Open the app in the morning and the curve shows the overnight low, when it occurred and how long it lasted, which tells you whether the heater coped or the fleece is needed. Humidity curves show when condensation forms, which is when fungal disease starts. Two years of storage lets you compare this spring with last.
Accuracy
Under a degree Fahrenheit and 2 percent relative humidity, as stated, is good for a consumer sensor and plenty for horticulture. Ten-second refresh catches short events like a door left open. Place it at plant height and out of direct sun; a sensor in sunlight reads the sun, not the air.
Range and Limits
Two hundred and sixty feet is the open-air figure. Through a house wall to a greenhouse at the end of the garden, expect far less, and the app only syncs when the phone is in range. The unit stores everything meanwhile, so nothing is lost; you simply read it when you are home. There is no Wi-Fi and no way to switch a heater or fan.
Display
The backlit screen is readable from across the greenhouse and the comfort face icon gives a glance-level summary. It runs on batteries, so it needs no power in the greenhouse.
Who Should Buy It
- Greenhouse owners who want to know overnight minimums.
- Seed starters and propagators tuning heat mats and humidity.
- Anyone comparing positions for a new greenhouse or cold frame.
Common Owner Complaints
Range through walls and the lack of remote access. Both are Bluetooth limits; a Wi-Fi model is the answer if you need them.
Alternatives to Consider
Govee Wi-Fi hygrometers add remote alerts through a hub. Inkbird IBS-TH2 is a comparable Bluetooth logger. A simple min-max thermometer records the extremes without an app.
Verdict
For understanding what a greenhouse does when you are not in it, a logging hygrometer is the single most useful instrument, and this one does it accurately with two years of memory for a modest price. Shade it, place it at plant height and read the curve every morning.
Full specifications
TempPro TempAir Bluetooth Thermometer Hygrometer with 260 Foot Range and Data Export FAQs
The damage happens when you are not looking. A log shows the overnight minimum, how fast the house heats after sunrise and how humidity swings, so you can set heaters, vents and watering correctly.
No. Bluetooth reaches your phone at home, up to 260 feet with clear line of sight. For remote access you need a Wi-Fi sensor.
The app exports the stored history as a file you can open in a spreadsheet to chart seasons or compare greenhouse positions.
At plant height, shaded from direct sun, away from the door. Sun on the sensor inflates the reading by many degrees.
