12 Best Temperature and Humidity Controllers for Grow Room in 2021

One of the most important aspects to keep in mind when growing cannabis plants is the humidity and temperature amount. They both play a crucial role in how well your plants will grow. To help you keep track of the humidity and temperature amounts in your grow tent or other growing space, you can use temperature and humidity controllers.

What is the Ideal Temperature and Humidity Amount?

Regardless of what type of grow space you use, you want to make sure it has a certain temperature and humidity level. The ideal temperature for a grow area is about 68-77 degrees Fahrenheit. This is warm enough to keep the plants happy, but not hot enough to make them shrivel up. Lighting can also help you achieve this temperature by keeping your growing area warm. However, always be sure that the lighting isn’t making the plants too uncomfortable as it shines on them.

The ideal overall humidity amount is about 40-70% for these plants. This is enough to help them grow without the space being too hot for them. However, this is just a general idea. The right temperature and humidity amounts depend on many aspects.

The Top Thermometers to Use

Below are some of the top thermometers you can use to help you keep track of the temperature and humidity amounts in your growing space.

ThermoPro TP55

This digital thermometer features a 4-inch-long touchscreen. It can switch between Fahrenheit and Celsius and will capture the temperature/humidity amounts in the room every 10 seconds. This model can measure temperatures from -58-158 degrees Fahrenheit and humidity levels from 10-99%. It also has a special indicator to show whether those temperatures are comfortable for the plants and whether you need to change the levels.

Besides the current temperature and humidity levels, this controller will also help to record detailed information about the room such as the maximum and minimum temperature and humidity levels that have occurred. This product can run for 24 hrs. and can be hung on the wall, propped up with its base, or hung on a magnetic surface with its back magnet. It needs an AAA battery to run and one comes with it.

AcuRite 00325

This digital thermometer can also work with a humidity gauge. It can record the highs and lows of the current air levels and can easily switch between Fahrenheit and Celsius. Its humidity gauge will help to indicate whether the humidity is at a high, low, or ideal temperature for your plants. This can help you to see whether you need to adjust anything in the growing space to help them grow better. This product can record temperatures from 32-122 degrees Fahrenheit and humidity levels from 20-95%. You can hang this on a magnetic surface or prop it up with its base in the back. It does need an AA battery to run and comes in a black, red, or blue color.

AnyPro Hygrometer and Thermometer

This device can measure both the humidity and temperature in your growing space easily. Its humidity meter will indicate whether the air is dry, comfortable, or wet which can help you see whether or not you need to adjust the air inside your growing space. Its temperature gauge can switch between Fahrenheit and Celsius and can record temperatures from 32-122 degrees Fahrenheit. This product will record the highs and lows for you. Besides the temperature and humidity levels, this product also has a time display. You can use the 12 or 24 hr. settings on this product to help you better monitor the conditions in your growing space. You’ll find these function buttons on the back of this model.

This product needs 2 AAA batteries to run and can be either hung up with its magnet or propped with its base stand.

The Top Heaters for Your Growing Space

If you find that the temperature in your growing space is consistently too cold for your plants, you’ll want to invest in a heater. Heaters can help to warm your growing area up, but keep in mind to always watch them to make sure they don’t end up overheating the space. Here are some of the top heaters that you should consider for your growing space.

Dr. Infrared

This heater is made of a durable steel design and runs on 1500W. It can quickly reach warm temperatures which you can adjust with its 2 dials. One dial will change the temperature levels (from a low to high setting) and the other dial will either turn this heater on its heat, fan, or off setting. This model is lightweight which means will be easy for you to move it around in your grow space. It’s also compact so it won’t take up much space while in your growing area. This device is protected from water splashes so if you happen to get some on it while watering your plants you don’t need to worry about it.

HydroFarm Seedling Heating Mat

This product is a large heating mat which you can put your seedling pot on to warm them. It can heat from temperature from 10-20 degrees Fahrenheit which is hot enough to help the seedlings quickly germinate. The heat is uniform so one area won’t receive more warmth than another. This heating mat comes in many different sizes and runs on 17W. It comes with a 6-ft. power cord so you can easily plug it in. This product also has special instructions printed on the top of the mat to help you learn how to best use it.

The Top Fans to Help Cool Your Growing Space

If the temperatures in your growing space tend to be very hot, you’ll need to look for a fan. Fans are very helpful at quickly cooling the air down in your growing space. Below are some fans to consider using.

Holmes Blizzard

This fan has a 12-inch width and can run on 3 speeds. You can choose one of the speeds depending on your preferences of how cool you want temperatures to be. This fan also comes with a sleep and breeze mode. The sleep mode will make the fan turn itself off after a certain time and the breeze mode will send a refreshing burst of air every so often. You can use this fan’s 8-hour timer to help keep it running constantly to help cool your growing area down. This fan can be controlled with a remote control and has cord storage in the back of it to help make storing it away easier.


This clip-on fan measures 6 inches. It has a 2-speed setting that you can use on your plants: high or low. The fan has an adjustable 120-degree tilting ability so it can easily move to where you’d like the air flow to be directed. It has 3 blades that are covered with a strong metal mesh covering. On the back of this fan is a heat emission escape to help prevent it from overheating while running. This fan runs on 20W and has a 5.2 ft. power cord. It’s also an energy-efficient option which means it can run for a long time without causing your electric bill to increase.

The Best Humidifiers and Dehumidifiers for Your Plants

If you’d like to add some more humidity or even reduce it in your growing space, you’ll want to make sure you use the right humidifiers and dehumidifiers for your space. Here are some products that are ideal to use for your growing space.

UR Power Humidifier

This humidifier has a large capacity (5 liters) so you can store a large amount of water in it. It has a low, middle, and high mist setting and will run quietly. Once all the water has been removed, this humidifier will turn itself off thanks to its auto shut-off feature. This humidifier can run for up to 14-17 hours.

DropAir Humidifier

This quiet humidifier can cover an area of up to 2,000 square feet. It has an automatic water control feature which will help it to monitor the current amount of water in it and alert you to when you need to refill it.

Ivation GDM36

This dehumidifier can hold up to 64 oz. of water. It can remove the humidity in a room that’s no bigger than 2,000 cubic feet. This machine will run quietly and will turn itself off once it reaches its capacity. An indicator light will also come on to help alert you to when you need to empty it.

Frigidaire FAD504DWD

This dehumidifier model can hold up to 50 pints of water. It comes with a humidity control feature which will help you to control the amount of humidity you’d like to have in your growing space. If you’d like to keep it continuously running, you can place it near a drain so it can automatically empty itself each time its capacity is reached. This product has a full tank alert which will make it turn itself off once its capacity is reached if you don’t use a drain. You can use its electrical controls to help monitor humidity levels and can easily move it around with its handle and wheels. This product comes with a 6-ft. power cord which is long enough to help make it easier for you to plug it in.

The Best Environment Controllers

Environment controllers help you to keep a closer look at practically every aspect of your growing space. This includes humidity, temperature, and CO2 levels. Below are 2 environment controllers that will help you easily monitor these levels in your growing space.













This digital environment controller runs on 120V and 14.5 amps. It has a variety of controls that you can use to monitor and adjust the temperature, humidity, and CO2 levels in your growing space. You can see which features are one and off with its light sensors. This controller will also help to record data so you can go back and check what a certain day’s levels were.

Titan Controls Saturn 6










This controller can help to monitor temperature, humidity, and CO2 PPM levels. It also has special carbon dioxide gas PPM controls. This product uses a 15-ft. remote sensor which has a photocell built into it. This photocell will help to keep the CO2 levels running during the day and stop it at night. You can easily monitor what features are on or off with its bright light indicators.

You’ll also find that this device records the minimum and maximum levels of the day. You can go back in its data log to check what certain levels were on a certain day. This heavy-duty controller is also made to be rust resistant and moisture free so you don’t need to worry about it being damaged while in your growing space.

The Best Humidity Levels for Certain Plant Stages

The different growth stages of your plants mean that they each have their own unique humidity levels (which was mentioned in the beginning of this article). Below are the ideal humidity levels for each plant growth stage.

  • Seedling Stage- You want to make sure the humidity levels are anywhere from 65-70%. These levels will help to open the pores of the plant to help it with its water intake so it can grow.
  • Vegetative Stage- For this stage you’ll want a humidity anywhere from 40-70%. This is lower than the seedling stage because at this stage you want to focus more on the roots. The humidity levels for this stage will help your plant grow deeper and stronger roots.
  • Flowering Stage- You’ll want to lower the humidity levels to 40-50%. This will help the plant to not focus mainly on growing, but rather flowering.

It’s important to keep these humidity levels in mind when using a controller to make sure that your plants have the right humidity amounts. As you can see from this information, using the humidity levels are crucial when growing cannabis plants. The right amount really depends on your growing amounts and location, so be sure to check to make sure you’re using the right amounts for your own plants.

Things to Keep in Mind

There are a few things you’ll want to keep in mind before using any of these products. Here is a little more about the things you’ll want to check for and consider before buying or using one of these products.


It’s important to check to make sure that the thermometer you’re interested in has a wide temperature range. This can help it to be more accurate in its recordings so you can better adjust the temperature and humidity levels in your growing space.


Heaters are helpful with warming your growing space up, but you’ll want to always keep an eye on them. If you have bright lights glowing on your plants while having a heater running, that could end up overwhelming your plants which could lead to them becoming very hot. If you plan to use a heater in your growing space, you might want to consider reducing the light levels in your growing space to prevent overheating from occurring.


If you use a fan in your growing space, make sure it isn’t blowing too much on your plants. This could end up making the plants fall over or even crack their stems because the air amount is too much for them.


For both types, you’ll want to make sure they have a large capacity. This can help to prevent you from having to constantly change or fill its bin up.

Also, make sure that with the dehumidifier you leave some humidity in the room. Cannabis plants need a little of it and removing all the humidity will only hurt them.

Environment Controllers

One thing to always look at with an environment controller is if it has a data log. This can help you to keep track of certain temperatures and other aspects during the day. It can also help you to see what levels your plants comfortably grow in.

Other Ways to Help Control Temperature and Humidity

In addition to temperature and humidity controllers, you can also use a few other things to help control these levels. You can hang wet towels in your growing space to help with high humidity and can also moisten the soil of your plants to help with this as well. To lower the temperature in your growing space you can dim or turn the lights off in it or even invest in a lower wattage amount.


These products will help to keep your growing area a comfortable environment for your plants to be in. This can help lead to happy plants which can lead to a great harvest. Temperature and humidity levels are vital to check when growing cannabis plants and the products in this review will help to make it easier for you to monitor them.