Which Greenhouse Thermometer Keeps Plants at the Right Temp
ThermoPro’s TP65 balances accuracy, range, and a large display for most greenhouse growers. Govee’s WiFi Thermometer Hygrometer H5179 adds phone alerts and history tracking for the same core readings. AcuRite’s 00613 covers basic budget monitoring without wireless features. Each option was compared on stated accuracy, humidity readout, and wireless reliability.
Greenhouse temperatures can swing 30 degrees between morning shade and midday sun, so accurate tracking matters more than it does indoors. ThermoPro’s TP65, Govee’s H5179, and AcuRite’s 00613 all measure temperature and humidity, but they differ in range, refresh rate, and how readings reach the grower.
Condensation and plastic walls throw off cheap humidity sensors more easily than they affect temperature readings. We compared specifications across probe placement, wireless distance, alert features, and build quality to separate dependable options from gimmicks.
How to choose
How Do Greenhouse Thermometers Work? A greenhouse thermometer pairs a temperature sensor with a display, either an analog dial or a digital screen. Many models add a humidity sensor, since trapped moisture affects mold risk and seed germination. Wireless versions place the sensor near plants and send data to a base station or phone outside the structure. Analog dials need no power and rarely fail, while digital sensors read faster and more precisely.
How Accurate Are Temperature and Humidity Readings? Most digital sensors claim accuracy within 1 to 2 degrees Fahrenheit, while basic analog dials run closer to 3 degrees off. Humidity readings vary more, since cheap capacitive sensors drift in consistently damp air. A stated accuracy of plus or minus 3 percent relative humidity or better is a reasonable minimum to look for. Placement near vents or dense foliage can shift a reading as much as the hardware itself does.
How Far Does Wireless Range Reach, and Do App Alerts Help? Manufacturer wireless range figures assume open air with no obstructions, so greenhouse glass, plastic sheeting, and metal framing typically cut real range by a third or more. WiFi-enabled models like the Govee H5179 sidestep this by relaying data through a home router instead of a direct radio link. App alerts matter most for overnight frost warnings or heat spikes when nobody is on site. A wired probe, such as the Govee H5100, avoids interference entirely since the cable carries the signal directly.
Where Should a Thermometer Sit Inside a Greenhouse? Condensation and high humidity shorten the life of sensors not built for damp conditions, so check the stated operating humidity range before buying. Plant-height mounting beats a spot near the roof, where heat pools several degrees above ground-level readings. Direct sun through the glazing can inflate temperature readings by several degrees, so keep sensors shaded. A ventilated spot near the center of the growing area gives the most representative reading.
The best picks, ranked
ThermoPro TP65 Wireless Indoor Outdoor Thermometer Hygrometer
A 500 foot wireless range keeps this sensor connected across most greenhouse layouts. Its 6.4 inch backlit display stays readable from across the structure, even in low light. Twenty-four hour high and low logs track temperature and humidity automatically, and the outdoor sensor holds up to negative 40 degrees Fahrenheit.
Pros
- Large backlit display readable at a distance
- Stores 24 hour min/max readings automatically
- Sensor withstands freezing greenhouse nights
Cons
- No smartphone app for remote viewing
- Base station needs AC power or batteries
Govee WiFi Thermometer Hygrometer H5179
Home WiFi lets this sensor push readings and history graphs to a phone from anywhere, not just within direct wireless range. Push alerts fire when temperature or humidity crosses a set threshold. Two AAA batteries run the compact sensor for months between changes.
Pros
- Remote alerts reach a phone from any location
- Free app stores months of reading history
- Two step WiFi setup takes only minutes
Cons
- Depends on a stable home WiFi signal
- Small display is hard to read outdoors
AcuRite 00613 Digital Hygrometer and Indoor Thermometer
One compact unit covers temperature and humidity without wireless features or an app. A shelf mount or hook near seedlings gives a quick glance reading. Comfort level icons flag at a glance when humidity runs too high for cuttings.
Pros
- Inexpensive way to add humidity tracking
- Compact size fits tight bench space
- Comfort icons flag humidity without reading numbers
Cons
- No outdoor sensor or wireless link
- Display lacks a backlight
ThermoPro TP25 Wireless Weather Station with 4 Remote Sensors
Up to four remote sensors track separate zones inside a large greenhouse at once. Rated wireless range reaches 1000 feet in open air, though greenhouse plastic and metal framing shorten that in practice. Each channel logs its own 24 hour high and low history.
Pros
- Monitors up to 4 zones simultaneously
- Long rated wireless range for open layouts
- Per channel min/max history tracking
Cons
- Range drops noticeably through greenhouse structures
- Larger base station takes up more counter space
Govee WiFi Thermometer Hygrometer H5100 Wired Probe
A wired probe on a 6.5 foot cable lets the display sit outside the greenhouse while the sensor stays inside near plants. App alerts cover both high and low thresholds for temperature and humidity. Data logs export as a spreadsheet for tracking trends across a growing season.
Pros
- Wired probe avoids humidity damage to electronics
- Custom high and low alert thresholds
- Exportable data logs for season-long tracking
Cons
- Cable limits sensor placement to 6.5 feet
- Needs home WiFi coverage to reach the greenhouse
La Crosse Technology C85845 Wireless Digital Thermometer
Daily, weekly, and monthly high and low records make it easier to spot trends across a growing season. Wireless range covers up to 330 feet between sensor and base. A moon phase and forecast icon add context for outdoor readings near the greenhouse door.
Pros
- Long-term min/max history beyond 24 hours
- Clear icons show humidity comfort level
- Basic forecast indicator included
Cons
- Buttons run small and fiddly
- No app or remote alerts
La Crosse Technology 104-1584B Analog Dial Thermometer and Hygrometer
No batteries or setup are needed, just a hook or stand near the growing area. A dual dial shows temperature and humidity side by side at a glance. Growers who want a reliable backup gauge alongside a digital wireless system often add this as a second unit.
Pros
- No batteries or app required
- Instant glance reading with no lag
- Works as a reliable backup gauge
Cons
- Less precise than digital sensors
- No data logging or history
How they compare
| # | Model | Temp range | Best for | Score | Price |
|---|---|---|---|---|---|
| 1 | ThermoPro TP65 Wireless Indoor Outdoor Thermometer Hygrometer | -40 to 140 F | Best overall | 9.4 | Check price |
| 2 | Govee WiFi Thermometer Hygrometer H5179 | -4 to 140 F | Best value | 9.1 | Check price |
| 3 | AcuRite 00613 Digital Hygrometer and Indoor Thermometer | 32 to 122 F | Best budget | 8.8 | Check price |
| 4 | ThermoPro TP25 Wireless Weather Station with 4 Remote Sensors | -40 to 140 F | Best for remote monitoring | 8.6 | Check price |
| 5 | Govee WiFi Thermometer Hygrometer H5100 Wired Probe | -40 to 158 F probe | Best for app alerts | 8.4 | Check price |
| 6 | La Crosse Technology C85845 Wireless Digital Thermometer | -40 to 140 F | Best for min/max recording | 8.2 | Check price |
| 7 | La Crosse Technology 104-1584B Analog Dial Thermometer and Hygrometer | -20 to 120 F | Best simple analog dial | 8.0 | Check price |
Frequently asked questions
What temperature should a greenhouse stay at?
Most vegetable and flower seedlings do best between 65 and 75 degrees Fahrenheit during the day and no lower than 50 degrees at night. Tropical plants often need warmer minimums, so check individual plant requirements.
Do you need a hygrometer in a greenhouse?
Yes, humidity affects mold, mildew, and pest pressure as much as temperature does. Most growers aim for 50 to 70 percent relative humidity depending on the crop.
How accurate are wireless greenhouse thermometers?
Mid-range digital sensors are typically accurate within 1 to 2 degrees Fahrenheit for temperature and within 3 to 5 percent for humidity, based on manufacturer specifications.
Can greenhouse humidity damage electronic thermometers?
Sustained high humidity can fog displays and corrode contacts on units not rated for damp conditions. Wired probe designs, like the Govee H5100, keep the sensitive electronics outside the humid zone.
What counts as a good wireless range for a greenhouse sensor?
A rated range of 300 feet or more leaves enough buffer for real-world signal loss through glass and plastic sheeting, which can cut effective range by a third.
Is analog or digital better for a greenhouse thermometer?
Digital units read faster and log history, while analog dials need no batteries and rarely fail. Many growers keep an analog dial as backup alongside a digital wireless system.
Where should a thermometer go inside a greenhouse?
Mount it at plant height near the center of the growing area, away from direct sun through the glazing and away from vents. Edge readings run hotter or cooler than the average.
Do WiFi greenhouse thermometers work without home internet?
No, WiFi models like the Govee H5179 need a home router connection to send remote alerts. Local readings still display on the sensor and app once back in range.
Best greenhouse thermometer for a large structure with multiple zones?
The ThermoPro TP25 supports up to four remote sensors, which suits growers tracking separate zones inside one large greenhouse.
Final word
ThermoPro’s TP65 covers most greenhouse setups with strong wireless range and a clear display. Growers wanting phone alerts should look at the Govee WiFi models, while a basic AcuRite or analog dial works fine for casual monitoring. Match wireless range and weatherproofing to the size and humidity of your specific greenhouse.
