What’s the Ideal Temp and Humidity for a Grow Tent?

Ideal grow tent temperature and humidity levels can vary depending on the plant you’re growing, but we generally suggest keeping a grow tent within these ranges:

Temperature: 62°F (17°C) – 87°F (31°C)

Humidity: 40 – 70%

This is the ideal range for both temperature and humidity, and if your levels fall outside of those ranges, you may want to look at buying something to adjust that.

Do I need a humidifier or dehumidifier in my grow tent?

First check your current humidity level in your tent using a hygrometer, which is an indoor humidity monitor. If your humidity is lower than 40%, you may want to buy a humidifier. Inversely, if your humidity is over 70%, you may want to look at buying a dehumidifier.

What dehumidifier should I buy?

We have written a popular post showcasing the 4 best grow room dehumidifiers for hydroponics. In that article we breakdown our favorites over a range of budgets.

What happens if humidity is too low in a grow tent?

Low humidity can cause plants to become dehydrated, which is not good. Dehydrated plants have a harder time taking in water that they need to grow.

This is why many greenhouses and conservatories feel humid, and it’s because plants do better with moderate to high humidity year-round.

grow tent humidity fan

What happens if humidity is too high in a grow tent?

High humidity in your grow tent is not ideal either. High levels of humidity can lead to mold developing on wet areas of your setup and even the plants themselves. Moldy plants don’t do very well, so make sure to keep your humidity between 40-70%.

If you’re using a hydroponics setup with water moving in various parts, be extra careful with high humidity. Mold has more opportunities to form around hydroponic systems.

How do I lower the humidity in my grow tent?

We’ve written a great post on how to lower the humidity level in a grow tent. There you’ll learn about products and tricks you can do to lower your grow tent’s humidity level.


Outdoor gardeners know that temperature and humidity are out of their control. However, indoor growing can present new challenges related to maintaining ideal temperature and humidity levels. Thankfully, there are a number of products out there to assist in maintaining optimal temperature and humidity range in your grow tent.

Start by buying a digital thermometer and hygrometer to check the current levels. If your levels are outside of the ranges mentioned at the start of this article, you may want to invest in a humidifier or dehumidifier and digital controllers.