How Hot Does a Shed Get in the Summer?

A shed can get extremely hot inside during the warmer temperatures of the summer months. Since sheds are usually just buildings that are uninsulated and have little airflow inside, they can heat up quickly throughout the day. When the sun is beaming down and temperatures are soaring outside, the temperature in your shed is likely toasty as well. Even on a mild day, a shed can get very hot inside.

In the hot summer months, a shed can reach temperatures of 120 degrees Fahrenheit or more inside. There are numerous things you can do to help decrease this temperature but unless your shed is shaded, vented, or fully insulated and air-conditioned, it will always be a hot and stuffy space.

Garden shed with window

I have found that my shed, which sits in the full sun 24/7, usually reaches 20 – 25 degrees above what the outdoor temperature is.

Sheds are built using different materials such as wood, metal, and plastic. The most often seen types are those made of wood. These are framed and finished similar to a house (at least in the United States) with the obvious difference of size and types of wood used.

They also usually remain unfinished inside since they are only used to store outdoor equipment. Rather than having insulation that helps to slow down heat transfer from outside the structure, a shed has no way to slow it down. This results in a building that heats up quickly and stays hot throughout the hot summer days. It becomes like a sauna that has trapped heat and is very uncomfortable inside.

Thermometer with shed temperature

If you are going to be spending more time in your shed and want it to stay cooler inside, you have a few options. Let’s look at some of those options below.

How to Keep a Shed Cool In the Summer

1. Utilize Shade Trees

The first important step in making your shed cooler is to place it in a shady area. If your shed is already in place, you may be out of luck. However, you can always plant trees but of course, you’ll have to wait years for them to grow and provide shade.

If you are purchasing or building a shed, be sure you place it in an area that sees some shade throughout the day. If it is placed in a shady area, you are less likely to see such extreme temperatures inside. It will still get hot but just by placing it in a shady area, you will be better off in the end.

2. Insulate It

An insulated shed is going to slow down the heat flow that finds its way inside your shed. However, if insulating the shed is all you do, it will not give you a perfectly temperature-controlled environment. It probably won’t even give you a comfortable environment at all. It might keep the temperatures from reaching extreme highs but you’ll need to combine it with other methods to make it more comfortable.

If the shed is in the shade and fully insulated, you will be well on your way to having a more temperate structure.

3. Make Sure Shed Has Proper Ventilation

Ventilation is important for a shed if you want it to maintain any type of pleasant temperature. Without ventilation, the heat that has built up inside has no way to escape with any type of breeze or cooler air coming in and out of the shed. Most sheds have vents in the gable area that allows airflow. With a vent on each side, this allows air to flow through from one side to the other. This can help to have a steady stream of air but may only have a cooling effect if the wind is blowing.

For better ventilation, you can also install a roof turbine vent. These help to pull hot air from the shed which will help to decrease the temperature.

4. Cover All Windows

If your shed is sitting in the hot sun and has windows in it, you will want to cover the windows with some type of reflective material. Similar to your car windshield, windows in a shed will allow the heat from the sun to heat the shed up in the same way it does your car. This will turn the inside area of the shed into an oven if left uncovered.

Installing simple reflective coverings on the windows can do wonders for maintaining a more pleasant temperature inside the shed. Combined with all the other tips mentioned above, it can help to decrease the overall temperature inside the shed in the hot summer months.

What is the Best Insulation For Sheds?

The purpose of the shed will likely determine the type of insulation you will want to use. If your shed is only used to store items and you aren’t spending time in it, it’s probably best to spend as little as possible on insulation. The insulation will help but it’s also a double-edged sword. It does slow down the heating process but as the shed gets hot during the day, it will also take longer to release that heat at the end of the day.

In reality, insulation isn’t going to be a great way to spend your money unless you plan on combining it with other methods of keeping it cool.

Let’s look at four of the best insulation types for your shed.

Fiberglass Batts

This is commonly used in home exterior walls, basements, crawlspaces, etc. It’s an affordable type of insulation with a high R-value. For a small shed, it will be a minimum expenditure and will give you the best bang for your buck. It’s easy to install but can be irritating to work with. As you work with it, you’ll have to deal with fiberglass particles flying around all over the place as you install it.

You will want to wear long clothing, gloves, and a mask to keep it off your skin and out of your lungs as you are installing it.

Reflective Insulation

This is more of a radiant barrier that will work great in combination with other types of insulation. However, you can also use it by itself to at least reflect some of the radiant heat. If installed correctly, this can help to decrease the temperature in your shed. However, it works best when combined with something else.

When combined with fiberglass batts or other types of insulation and installed correctly with a proper gap as recommended, it does a great job at warding off heat that would otherwise be collected inside the shed. This radiant barrier is affordable and very easy to install. It can be installed with a pair of scissors and a staple gun in the ceiling and walls of the shed.

Foam Board Insulation

Foam board insulation is easy to work with and depending on the size of your shed, you’ll only need a few sheets of it to complete the project. This typically has a decent R-value but not quite as high as fiberglass batts will. This means that it won’t slow down the heat as much as fiberglass will.

However, it does make for a safer installation without fiberglass flying all over the place. It can also be combined with the reflective foil mentioned above to create a double layer of insulation.

Spray Foam Insulation

This will be the most expensive and difficult type of insulation to install. It may be best to have a professional company do this for you if you decide to go this route. If not, you can buy spray foam insulation kits that give you everything you need to complete the job.

The R-value on foam insulation is quite high so it has the potential to do the best job at slowing the heat transfer. If you are really concerned about the temperatures in your shed, and you have a very small shed, spray foam is a great way to insulate it. Its moisture-resistant properties make it a great choice for an outdoor building.

If you are setting up a home office or a workshop complete with air-conditioning, this type of insulation will help keep it nice and cool inside. If not, stick with the cheaper methods as these will work great for a shed.

Bottom Line

Sheds get very hot inside during the hot summer months. If you live in areas that see temperatures rise above 100 degrees Fahrenheit, you will see some extreme temperatures inside the shed. Even reasonable outdoor temperatures can result in sheds that see temperatures rise over 100 degrees.

This can be damaging over time to items that might be stored inside. The constant heat can break down plastic and rubber over time which can be damaging to tools and other items you might have stored inside. While there just isn’t much you can do for a shed that is constantly in the full sun, if you are able to take advantage of a shady spot, proper ventilation, and a little insulation, you will be able to keep the temperature more reasonable.