Grow Room Temp 85? Let’s Get the Solution!

Grow room temp 85 degrees? Well, you are undergoing a tough time. Such a level of temperature in the grow room may make your grow system go in vain. Therefore, you need to take immediate measures to save the lives of your grow tent plants.

However, you have nothing to worry about if you experience such a high temperature in your grow tent. This is because every grower in the world has to face this kind of issue at least once in his or her grow room planting career. But what is the solution? Let’s dig into the article to learn about the solution.

Is 85 Degrees Temperature Too Much for Growing Plants in a Grow Room?

The ideal range of temperature for growing plants in grow rooms is 68 degrees to 82 degrees for different stages of their lives. So, it is apparent that if the temperature exceeds 82 degrees, your grow room is undergoing a high level of temperature.

Now the question is whether 85 degrees is too much or not. Well, the answer is that it is too much for the plants if they are at the early stage of their lives. One the other hand, if the plants are at the vegging stage, they are capable of bearing such a level of high temperature.

However, if you leave your plants at 85 degrees of temperature for a long time, the plants will begin to face a number of issues. And when the temperature exceeds 85 degrees, your plants will likely begin to die in a drastic condition. Therefore, it is a good decision to decrease the temperature when it reaches 85 degrees or above.

What Are the Reasons for Having Grow Room Temp 85 Degrees or Higher?

Let’s learn the most common reasons for a high level of temperature in your grow room. This will help you avoid high temperature in the grow room in the upcoming days.

Poor Air Circulation

Air is the heart of your grow room. So, if it doesn’t circulate properly, your grow room temperature will increase alarmingly, leaving the plants to get stumbled to survive.

This happens when you don’t have an effective fan in your grow room. However, there are many kinds of fans to use in a grow tent. But we recommend using an oscillating fan. This type of fan can make the air reach every corner of the grow room.

Poor Air Exchange Rate

This is a big issue faced by a great number of growers across the world. When there aren’t enough facilities for air exchange, the hot air cannot go out of the room. This makes your grow room hot, and the temperature exceeds 85 degrees.

In order to fix the issue, you can take a number of measures. But the most effective measure is to use an extractor fan. For greater performance, you can use the combination of an input fan and an extractor fan. Thus you can boost the air exchange rate easily and effectively.

Low Humidity in the Grow Room

Many growers think that there is no relation between humidity and temperature. The reality is that these two factors are equally related. If one factor is not ideal, the other factor will be affected. To clarify, low humidity plays a vital role to increase the temperature in the grow tent.

Therefore, it is obvious that you need to make sure a high humidity in the grow room to decrease the temperature level. To be specific, try to raise humidity above 60% when the plants are in vegetative mode. On the other hand, you have to raise the humidity above 40% if the plants are in flowering mode.

Not Maintaining Light Sources Properly

Well, if you think that you are doing good by hanging grow lights close to the ceiling, then you are living in the fool’s paradise. By doing so, you can never decrease the overall temperature of the room. At best, it can help you avoid direct temperature.

The proper maintenance of the light sources requires you to switch off half of the grow lights for some time. For instance, if you have 4 grow lights in the room, switch off two of them. This will help you decrease the temperature to a great extent.

What Else Can You Do to Decrease Grow Room Temperature under 85?

There are many things you can do while you are on your way to decreasing the temperature of your grow room. But it is one of the most troublesome journeys out there. That is why you might want to have a shortcut solution. Well, in that case, you can relax with ease and comfort. Yes, we are not talking about Aladin’s Lamp. This is a real solution for you. Choose one of the following steps in this regard.

Use a Grow Tent Air Conditioner

Using a good grow tent air conditioner is the best shortcut way to take control over the temperature of your grow room. If you can afford a grow tent portable air conditioner, you are all set. With the help of the air conditioner, you will be able to control both temperature and humidity. Thus, it really works like Aladin’s Lamp.

BLACK+DECKER BPACT10WT Portable Air Conditioner, 5,500 BTU DOE (10,000 BTU Ashrae), White
  • QUIET & POWERFUL - Our 6,000 BTU DOE (10,000 BTU ASHRAE) compact air conditioner (16.5 x 11.5 x 26 in,) will keep you cool and comfortable all summer. An adjustable fan speed cools the air to 65°F at the coolest setting. Sleep mode makes it extra quiet while you rest

Use a Grow Room Temp Controller

In case you don’t want to use an air conditioner for your grow room, you can choose a grow room temperature controller. This tool will allow you to automate your grow. That is to say, you can stay on the couch while the grow room controller is taking the lead to control the environment of the grow room. With such a controller, you can easily control humidity, moisture, fan speed, grow lights, and CO2.

Why Should You Be Aware of High Temperature in Grow Room?

A great number of indoor growers don’t pay any heed to the problem if they face an extreme level of temperature in their grow rooms. This is because they think that plants are capable of tolerating high temperatures. If you are one of those growers, then you are on the wrong track.

The fact is that indoor plants are good to tolerate temperatures between 70 to 80 degrees. This range is highly good for many plants in the field. When the temperature exceeds the range, the plants of the grow tent faces numerous problems.

According to Hortnews, high temperature is unfavorable for most of the indoor plants. Many of the plants begin to lose satisfactory rates of polysynthesis when the temperature exceeds 85 degrees. As a result, the process of making sugar is hampered. Thus, your plants grapple with the temperature to survive.

Besides, when the temperature is high in the grow room, the roots and leaves of the plants are extremely affected. But how? Well, plants have little holes on their leaves, and they pass water through these holes when they have to cool themselves. This process is called stomata.

With the help of stomata, the process of transpiration occurs. And transpiration helps the plants cool their roots. That said, if the process is hampered, the roots of your plants will get hot. As a consequence, the roots will begin to dry, leaving the plants to be doomed.

What Are the Appropriate Ambient Temperatures for Different Stages?

Trees and plants don’t always need the same level of temperature. They require different levels of temperature in different stages of their lives. So, you should not provide them with the same temperature all the time. If you do so, you will unintentionally kill your plants.

Therefore, it is obvious that you must learn the proper guide of providing grow room plants with the necessary temperature. In this case, the following information will help you with a great deal.

Temperature for Seedlings

Most of the grow tent plants require you to provide them with 72 degrees to 82 degrees temperature. Make sure the environment is not exceeding 82 degrees. If it exceeds 82 degrees and reaches 85 degrees, then all seedlings are at risk to taste premature death.

Temperature for Vegging Stage

At this stage, plants need lights approximately for 18 hours a day. While providing them with sufficient light, you might be increasing the temperature in the grow room. Remember, when the plants are at the vegging stage, you should maintain the temperature between 68 degrees to 78 degrees.

Temperature for Flowering Stage

It is considered to be the most important stage in the life of a grow tent plant. So, you must be careful while maintaining the temperature in the grow room. According to experts, you should provide your plants with 68 degrees to 77 degrees temperature.

The ranges discussed above are not favorable for all kinds of indoor plants. That is why it is better to learn about the types of plants you are growing before maintaining temperature. However, for 99% of plants, the ranges are favorable. So, if you can’t find out the exact temperature range for your grow plants, then you can go with the above-mentioned ranges without any worry.

How to Detect Temperature in a Grow Room Easily and Effectively?

To detect the temperature of a grow room is one of the easiest jobs in the world. You don’t have to a professional do so. Even you don’t need a tool to accomplish the job. If you experience the following issues in your grow room, you can be pretty sure that the temperature is high in the room.

  • Necessary oils for the plants are lost
  • The plants are not growing anymore
  • Flowers are imperfectly formed
  • Premature births of fruits in the plants
  • The plants are sweating heavily

However, if are a lazy grower, you can buy a grow room controller in this case. A grow room controller will let you know when the temperature is too high. It will also help you control the environment without causing you much trouble.


You have so far learned about the correct temperature of a grow room. Now you know whether 85 degrees temperature is too much for the growth of your plants or not.

So, take necessary steps when you face the grow room temp 85 degrees. Otherwise, you will be responsible for the health of your plants. If they die premature deaths, you have no one to complain about. However, if you still have any questions regarding grow room temperature, don’t hesitate to let us know by commenting below.

Leave a Comment