Are you concerned about the humidity level of your indoor garden? Whether you have a full greenhouse or a small grow tent, humidity plays an important role. Plants need a certain humidity level to thrive. Different plants need different passive temperatures and humidity levels.
A hygrometer can be used to measure and monitor the humidity levels of a room. We've taken a look at some of the best hygrometer models on the market. These are our top recommendations. Whether you're a casual gardener or a serious professional, there is a hygrometer to suit your needs.
Top 8: Best Hygrometers
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The TP50 from ThermoPro is our top pick overall because of how convenient and easy to use it is. In addition to showing you the data and information, it also has a comfort indicator. This tells you whether a room is dry, wet, or at average comfort levels at a glance.
If you're just getting into indoor gardening, the comfort indicator can be very helpful. It's not always easy to remember the exact humidity range that your plants need. But you can easily remember whether they need a dry, wet, or average environment.
In addition to functioning as a hygrometer, the device also has a thermometer that measures temperature. Both measuring systems have a high degree of accuracy. The thermometer has a margin of error of 1 degree Fahrenheit, while the margin of error for the hygrometer is 2 to 3 percentage points.
Since the device is so accurate, you can measure even the tiniest changes to your inside greenhouse or grow tent. The device will give you a sense of how the temperature and humidity change throughout the day. The measurements are updated every 10 seconds, so you always know that you're looking at the most recent reading.
The device keeps track of the high and low temperatures in an area. It will show you the highest and lowest temperatures and humidity levels over the past 24 hours, which lets you see how your inside space is fluctuating.
In addition to being used for gardening, you can use this device to improve your home environment. The monitor will tell you whether your house is too dry, which might lead to irritation, or whether it's too wet, which can lead to the development of mold and mildew. It can be installed in your freezer or used in a reptile tank.
The design comes with two different mounting options. The included stand allows you to mount the product on a counter or shelf, so you can always see the reading when you enter a room. If you don't have shelf or table space, don't worry. There's also a magnetic back that lets you attach the device to a fridge or other magnetic surface.
The power source is a single AAA battery, which comes in the package. Replacing the battery once the initial power runs out is a simple affair.
This is a four-pack of miniature hygrometers and thermometers. Each device will show you the temperature and humidity reading of a room in real time. If you need to monitor several rooms in your house or several different grow tents, this is one of the best choices.
The meter is designed to show you the humidity level of a room in large digital print. The temperature is in the corner of the device. Temperatures are shown in Fahrenheit rather than Celsius. Since there isn't an option to switch to Celsius, this might not be the best for Canadians and others who use Celsius measurements.
The built-in probe allows the device to monitor the temperature and humidity levels in real time. Each device is made for use indoors.
The hygrometer can measure humidity levels of 10 to 99 percent with a margin of error of 5 percent. The thermometer can measure temperatures of -58 to -158 F, with a margin of error of 2 degrees.
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This is another good option. If you just need a monitor that tells you your real-time information without a lot of extra bells and whistles, this small investment works wonders. In addition, the size is less than the length of an average finger. You can place it in even the tiniest growing areas without a problem.
The design offers a quick response, showing an updated temperature and humidity reading every ten seconds. You never need to worry about the monitor displaying outdated information. Temperatures and humidity ratings are taken using four sensitive vents, so you have the most accurate combined information.
This has one of the most advanced humidity sensors on the market, thanks in large part to the four vents. Humidity is measured to within 1 percentage of accuracy. If you need to keep your plants in a very specific humidity range, the accuracy of this device is helpful.
The device can measure humidity at 10 to 95 percent and temperatures at -58 to 158 F. Information is displayed on an easy-to-read digital screen.
Since the design is so small, it can be easily incorporated into cigar humidors, incubators, reptile tanks, musical instrument cases, and any other area that needs humidity monitoring.
The manufacturer includes a 100 percent satisfaction guarantee with your purchase. If you aren't satisfied for any reason, you can get a refund. That makes this one of the most risk-free options on the list, especially since it's so affordable.
ThermoPro has designed a variety of different indoor hygrometers. This is the next one to make our recommendations list. The reading shows both the temperature and the humidity level in real time. If you want a more simple and inexpensive interface than the other ThermoPro, this is a good choice.
Unlike the more advanced ThermoPro design, this option does not tell you at a glance whether conditions are dry or wet. But there is a smiley face indicator that will tell you whether conditions are comfortable for humans or not. This makes it easy to gauge whether your plants are functioning in their necessary range.
The thermometer has accuracy readings to within 1 degree Fahrenheit. Meanwhile, the humidity readings have a margin of error of 2 to 3 percent. You can keep track of the fluctuating humidity and temperatures in your growing space throughout the day.
Like the TP50 hygrometer, this digital interface refreshes once every 10 seconds, so you're always looking at the most recent reading. The compact display makes it easy to use in small spaces, while the numbers are large enough to read at a distance.
Another ideal feature is that you can toggle between Fahrenheit and Celsius on the thermometer. This makes the device ideal for people who live in countries other than the US. Many other thermometers only display temperatures in Fahrenheit.
The design comes with three different mounting options. You can attach an included stand to display it on a table or shelf. You can also stick the magnetic back to a refrigerator or use the hanging hole to hang it on a hook.
The device is powered using a single AAA battery, which is included in the package. Thanks to the energy-saving construction, a single battery can last for 18 to 24 months at a time. Once it is time to replace the battery, you can do so easily. AAA batteries are easy to purchase at any grocery store.
This is one of the more advanced digital hygrometer designs on the market. It shows you a large amount of data in addition to the current temperature and humidity level. You can see the past high and low temperature and humidity as well.
Unlike the previous items on the list, this hygrometer can be remotely monitored. You'll first download the Govee home app, then you'll follow the instruction manual to pair your device. It only takes a few minutes to do. Once you do, you'll be able to see your readings on your phone in real time.
The Bluetooth range is 260 feet. You can find out about any changes to the growing space right away. If you need to monitor your plants constantly to keep their growing conditions stable, this feature might appeal.
The hygrometer takes measurements with a 3 percent margin of error. Meanwhile, the highly advanced temperature system has a margin of error of just 0.54 degrees Fahrenheit. It also displays the current temperature to within a tenth of a degree for greater accuracy.
You can program the refresh speed to keep your data updated. It's possible to have the device refresh at speeds of up to every two seconds. That's significantly faster than any of the prior options.
Also part of the design are the comfort level indicators. The screen will tell you right away whether the room is wet, dry, or comfortable. You'll be able to ensure that your plants have the right biome without struggling to interpret numbers.
You can program the app to notify you if the humidity or temperature moves out of your desired range. Simply input your necessary humidity levels. You'll get a notification if anything happens. That means that you'll be able to adjust your indoor environment immediately without needing to constantly check on your plants.
The app also gives you free storage of your data. It will hold the past 20 days of data readings. In addition, it will compile these findings into a curve graph, which will let you see how the data has changed over time. The past two years of data can be exported into CSV for examination as well.
That makes this an excellent choice for scientists and agricultural professionals who need to monitor their data closely.
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This 2-pack of hygrometers from Jedew is made for monitoring both indoor and outdoor humidity. It shows your temperature and humidity level in real time. Unlike the other items thus far, this hygrometer has a round display instead of a rectangular one.
The gauge can be used in greenhouses, outdoor areas, basements, bathrooms, incubators, reptile tanks, and baby's rooms. Wherever you need to monitor humidity and temperature, this option will serve you well. It also displays temperatures in Fahrenheit or Celsius.
The temperature readings are shown to be within 2 degrees Fahrenheit of accuracy. Meanwhile, the accuracy of the humidity is within 5 percentage points. That's not the most accurate on the list, but it is sufficient to make sure most plants are within their optimal growing zone.
The quick measuring response takes new data readings every 10 seconds. This also has more vents than any of the previous options on the list. There are 24 different openings, and average readings are taken by combining air from all of them.
The temperature measuring range is from 32 F to 158 F. This is good for most conditions, but it means that the device won't work for monitoring a freezer. Humidity levels can be measured from 10 to 90 percent, making this ideal for most indoor growing needs.
The exterior of the device is made out of durable PVC plastic. This material is more lightweight than metal, but it won't crack like cheaper plastics. The miniature size means that you can carry the device wherever you need it.
The applicator also makes this a versatile option. You can stick the monitor to a wall or mount it on a desk. As long as you have a smooth surface, you can mount it.
Do you have a lot of different areas that need monitoring? Maybe you run a professional greenhouse with many different environments, or maybe you need a humidity monitor in each room of your house for health reasons. Whatever your reason, this 12-pack has enough monitors to suit your needs.
The thermometer can measure temperatures of -58 to 158 Fahrenheit, with an accuracy of 2 degrees Fahrenheit. Meanwhile, the hygrometer can measure humidity levels at 10 to 99 percent with a margin of error of 5 percent.
That margin of error isn't the lowest on the market. But as long as you don't need to keep your plants at extremely specific temperatures, this is one of the most affordable bulk packs of hygrometers you can buy.
Since the size is so small, the monitors can be used in almost any place. Whether you need to monitor a greenhouse or the inside of a jar, the display can suit your needs. You can place it in the corner of a room or grow tent without it getting in the way.
Batteries are included. The display will only show the temperature in Fahrenheit, so keep that in mind if you usually measure in Celsius.
This is another great choice for people who want a high-information display. The screen will tell you the current temperature and humidity, the high and low of the past, and whether the humidity level is comfortable for indoor habitation.
There are two mounting options. You can use a clip to place it on a shelf or desk, or you can use the magnetic backing to place it on a refrigerator.
The device can take humidity measurements at 16 to 98 percent, so it's great for damp conditions. It can also measure temperatures at 32 to 122 degrees Fahrenheit or 0 to 50 degrees Celsius. The design is portable enough to be used in almost any indoor grow area.
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No matter what kind of plants you're growing, there is a hygrometer to suit your needs. People with multiple rooms should get a device with multiple sensors. If you want to monitor your device remotely, look for one that connects to your smartphone with an app.
Our top pick overall is the ThermoPro TP50 hygrometer. This hygrometer displays a variety of important information in an easily-read digital screen. It also tells you whether the numbers are dry, wet, or comfortable for human living. This lets you know at a glance whether your plants are in the right conditions.
If you need to monitor multiple areas, we recommend the Veanic four-pack. Each of these miniature displays will show you the temperature and humidity level of a room. They are simple devices that give you real-time information. Just keep in mind that they won't show the highs and lows of previous readings.
If you want a highly advanced system that stores your data over time, you'll want to consider the Govee 2-Pack. These monitors connect to your smartphone through an app. They will give you notifications if the humidity falls outside a desired range. In addition, they let you view graphs of past data, and you can export two years of data to CSV format.
For those who need to measure the humidity of every room they use, we recommend the Frienda 12-pack. Each pack comes with 12 different monitors that will show you the temperature and humidity of a room in real time. These are super affordable and have a relatively high degree of accuracy.
Frequently Asked Questions
Hygrometers are used to measure how much humidity is in the air, otherwise known as a space's relative humidity. Past versions of the device were crude dials that showed an estimate of the percentage. Nowadays, we can get extremely accurate hygrometer readings using digital technology. Today's hygrometers also tend to include a variety of other features.
A hygrometer is most often used by indoor gardeners. If you have your plants indoors, you need to control their growing environment. That includes keeping track of the humidity levels in the room. Different plants need different humidity levels and average temperatures to thrive.
Hygrometers also have a variety of beneficial features outside of a garden environment.
Most hygrometers are calibrated in the factory. As such, they're ready to use right out of the box. Some might connect to an app, which allows you to access your readings remotely. If that's the case, you'll need to download the app to your smartphone and connect the sensor.
The device will come with instructions for how to turn it on and where to place it. As long as it's somewhere in the area you need measurements, you shouldn't have a problem.
In addition to being used for indoor greenhouses and grow rooms, some of the purposes a hygrometer might be used for include:
There are many different features that hygrometers can have. But some are more important than others. If you know what features you're looking for, it will be easier to select the model that suits both your needs and budget.
First of all, you need to consider the accuracy of the device. Even with all of today's technological advancements, there is no perfect hygrometer. However, the margin of error is smaller in some than others. Hygrometer manufacturers will tell you the margin of error in the specifications or description of the product.
The majority of error margins are 2 to 3 percent relative humidity. If you need extreme accuracy, look for margins of less than 3 percent.
There are several technological features that you might find in a hygrometer. For example, it might be paired with an app on your smartphone. This allows you to monitor a room's humidity without needing to check the device itself. You can see exactly how humid the room is from outside the house.
Some of the smartphone-paired devices work with WiFi. There are others that pair to Bluetooth devices. Bluetooth enablement lets you see the readings even when you don't have access to WiFi. But there tends to be a short range of connection when you use Bluetooth instead of WiFi.
The vast majority of digital hygrometers will show you the highest and lowest humidity level over the past 24 hours. There are some models that can show you the highs and lows from longer periods of time, such as the last week, month, or the entire life of the device.
Knowing the highs and lows of your humidity levels helps you see how much your humidity is fluctuating. It also gives you a better sense of your interior temperature and average humidity with your current setup.
You might only have one grow room that needs monitoring. But many gardeners need to monitor the interior humidity of multiple rooms. If you have different plants that need different humidity ranges, you might calibrate the interior of multiple rooms instead.
If you do need to monitor multiple locations at once, it's best to look for a hygrometer with multiple sensors. With these designs, the sensors are typically faceless. They connect to a master informational panel, which shows you all of the readings at once.
Many apps let you monitor several sensors at once. The number of sensors you can monitor will depend on the app. Some allow for unlimited sensor installment.
You'll also want to take the size of your device into account. Some hygrometers are more compact than others. If you're monitoring a small interior space like a compact grow tent, you'll want a device designed to save space.
In the same way, you might want to consider the installation method of the device. Can the sensor be placed on a wall? Does it need to be put on a shelf or a table? Do you have enough room to put it down?
The final feature to take into consideration is the interface. How easy is the device to use? Most devices will have a digital screen that shows you information in real time. If you're monitoring multiple locations, you'll want a user interface that lets you access all of your data quickly and easily.
Advanced hygrometers might have extra technological features or extra monitoring capabilities. But most people won't need all of the extra bells and whistles. Minimalist devices have easily-accessible information, while more advanced devices have more detailed readouts.