Cannabis humidity

Easy ways to control temperature and humidity in the grow tent

Easy ways to control temperature and humidity in the grow tent

Along with the light, temperature and humidity are crucial deciding factors when it comes to producing big and potent yields of Cannabis. Creating the perfect environment indoors doesn’t take much effort, and therefore it is an absolute must, given how beneficial it is. 

Today we are having a look at 3 practices that will help you to create a paradise for your plant. Trust me, the buds will show a hell of a gratitude after harvest.


To begin with, an easy control of temperature and humidity is by far the biggest advantage indoor growers have over the folks who prefer to grow in a backyard. Since it is the only way to consistently achieve high quality yields in a reasonable amount of time. 

Therefore, not taking this advantage is madness! An indoor grow essentially allows to create the perfect environment for the plant and reduce its stress to minimum level. 

If the temperature and humidity is too low it negatively affects the plant’s development which results in smaller size and overall lower quality of the buds. On the other hand, too high temperature and humidity makes the environment highly favorable for mold and fungi. 

The more the tent growth climate moves away from the plant’s preferred temperature and humidity, the more severe and likely the potential consequences. Maintaining a sweet spot is a key to producing buds that you and your friends will remember forever.


First of all, let’s set the ideal measures you should be aiming at. The perfect temperature for Cannabis according to the industrial growers is 23-26 C. Ideal humidity is not constant and depend on the growth stage of the plant.


Hygrometer and Thermometer will be your best friends to keep an eye on it. Ideally you would like to stick them both onto a wall of the growing tent.

Setting up an effective system to control moisture and temperature consists of implementing some best practices and technology. Mostly it is all about doing all the little things  right. Here is the list of 3 things you need to do in order to maintain the aforementioned values.



While it is the most obvious to control the temperature it is also the one that makes the biggest impact. Earlier I wrote a guide on how to organize an efficient airflow in the growing tent. Check it out and you will know how to determine which size of the fan you need and where to place it.

Although adjusting fan speed sounds pretty simple, this skill needs to be mastered over time because it involves taking into consideration a fundamental temperature and humidity principle called “relative humidity“.

“Relative humidity” is the percentage of moisture in the air in relation to how much water the air can hold at a given time.

This principle exploits the fact that warmer air can hold much more moisture than cold air, meaning that humidity is directly dependent on temperature. The practical implication is that increasing the fan speed reduces humidity as moving air dries up moisture.



During photosynthesis, plants absorb carbon dioxide and release oxygen into the air. However, during the night plants behave similarly to humans. They absorb oxygen and release carbon dioxide into the air.


Excess amounts of carbon dioxide within a tent is a major contributing factor when it comes to high humidity. Bushy plants are the biggest carbon dioxide producers. Therefore, if you really struggle against the high temperatures, don’t hesitate to trim the most robust branches. 


If your tent looks like this trimming some leaves will be a great idea

This practice is exceptionally useful when the plant has started blooming. You can see where the flowers are forming and which branches have nothing but leaves. Feel free to remove them as they do not contribute to the final yield and quality at all.



Even though properly set up ventilation from the start is sufficient to provide comfortable temperature and humidity for the plants. Some growers use the help of the commercial units, as those are the most efficient way in getting the exact numbers you want.

I would say that they are definitely useful when it comes to growing in big volumes or aiming to achieve close to perfect results. However, if you are just starting with a couple of plants. Mindful control of ventilation will do the job just as good.

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