Hello! This article will explain the best temperature to grow marijuana indoors. We’ll focus on optimum temperatures and how they can affect your plant.
Before growing your cannabis, it’s essential to know that the plant prefers a specific range of temperatures for optimal growth. Deviating too far from this range can hurt your plants’ yields and growth rate. Especially for new growers, you want to do your best to keep your plant within the optimal temperature range. You can find a full range of requirements for growing marijuana indoors in our article, “Growing Cannabis: What are the Requirements?”
What are the best temperatures for growing marijuana?
As stated above, your plant will grow best between 65°F – 80°F (18°C – 26°C). However, this is just an average. Plants grown indoors can be heated to these temperatures by artificial light bulbs and heaters. Although it’s possible to veer off the optimum range, it can decrease your plant’s growth rate and yields.
In general, it’s best to keep temperature fluctuations as small as possible. The more minor your temperature variations (and the further from your plants’ optimal temperature), the better your yield. If you deviate too long outside of these ranges, your plant will begin to suffer.
Keep in mind that these temperatures are for plants grown indoors.
You’ll undoubtedly want to check out our article on the best temperature to grow weed outdoors if you grow outdoors!
Your plants should thrive if you keep a constant temperature of around 70°F (21°C). Some species of cannabis can grow outside in colder climates without any problems!
Please note that you should never expose your plant to temperatures below 65°F (18°C). Forcing a plant into a state of dormancy can cause irreparable damage or even kill the plant. If you live in a climate that can get below 65°F (18°C), it’s best to grow a different strain.
In addition, you should never expose your plant to temperatures above 80°F (26°C) for an extended period.
Above this temperature, you’ll start seeing decreased growth rates and yields. Your plants can survive high temperatures for a short period, but anything longer than a day can cause damage.
It’s important to note that colder temperatures don’t always coincide with a dimmer light source. You can have a bright light source and still experience cold nights due to the lack of heating from the light source itself. With this in mind, keeping your temperature as constant as possible is best.
Marijuana Plant Size and Temperature
If you’ve got a massive 50-light to grow op and want to crank the heat up to 85°F (29°C) for a couple of hours, your yield won’t be affected much. If you’re starting and growing a single plant under a CFL grow light, keeping the temperature as stable as possible is essential.
Remember: if you deviate too far outside the optimal temp range for too long, your plants could suffer greatly. While cold nights won’t affect plants with larger leaves, such as Sativa, Indica plants with smaller leaves are more susceptible to damage.
If you’re looking for some help growing your cannabis plants indoors, I’d recommend checking out this article on the best way to germinate marijuana seeds. If you want to dive right in and start growing weed, consider reading about where I am in my growth journey.

Until next time, happy growing!
For more information on temperature requirements for growing cannabis, check out our article! Incorrect temperatures can lead to poor growth rates and yields, so it’s essential to research what is required beforehand.
Now that you know the best temperature range to grow marijuana inside, you must choose where to put your plants. What is the best place for them?
I’ll explain in detail in my next article! Stay tuned for more updates on how to grow marijuana indoors.
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