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Can an Indoor Extension Cord Be Used Outside? (Explained)

Electricity is a crucial component in our day to day lives where most of our electronic appliances starting from lights to refrigerator and microwave depend on it to operate. 

However, besides its use and applications indoors, we might often feel the need to use electricity outdoors as well for several occasions. 

But whether an indoor extension cord can be used outside to conduct electricity is debatable – and the details regarding that issue have been discussed below.

Can an indoor extension cord be used outside?

It is excessively dangerous to use an indoor extension cord outside and is strictly not recommended to leave them outside for more than a day. Indoor extension cords are not built for rugged use and thus they would break down over extended use outside and put your house at fire or shock hazard.

An indoor extension cord is an extension cord that is manufactured for indoor use with the minimal level of insulation and being more vulnerable to physical damage because they are not expected to be exposed to harsh environments. 

For this reason, the female socket molded into the end of the cord is not rated weather tight – these factors are not of much concern since they are not subject to harsh conditions indoors. 

As a result, if these cords are left outside for more than a day or two, they might start wearing out and lead to fire or shock hazards.

Weather conditions such as harsh sunlight is enough to break down the insulation of indoor cords, but outdoor extension cords. 

On the other hand have thicker, rain tight and safer rubber molded at the end of the cord as well as having special covering that protects it from harsh environmental conditions. 

Extension cords made for outdoor use are available in several gauges that represent their amperage rating and have a thickness in accordance to that.

But many people tend to not buy a separate extension cord for outdoor use if they need power outdoors for a short time – in such cases, the cord is needed outside for a day or two at max. 

This behavior makes you vulnerable to several risks since those indoor extension cords are not designed to withstand the temperature, moisture or heat outdoors and they also lack the protective sheath – which increases its vulnerability to breakages. 

Therefore, if you use indoor extension cords outside – it could be rugged or break and leave your house exposed to fire or shock hazards. You still can use indoor extension cords outside but you must be excessively careful and follow safety procedures.

Is it dangerous to use an indoor extension cord for outdoor Christmas lights?

Christmas is one of the largest festivals celebrated throughout the US and other parts of the world as well – and to reflect this occasion, many houses are decorated with sparkling lights and many other decorations both indoors and outdoors. 

And often these decorations outside are lit up using indoor extension cords – which is excessively dangerous since those cords stay outdoors for many days. 

Indoor extension cords are not designed to handle the temperature, heat and moisture outside and thus using them outdoors increases the risks of fire and shock hazard.

Why should you not use an indoor extension cord outside?

Indoor extension cords are designed to be used strictly indoors, using them outside is dangerous due to the following reasons:

Lack of thick insulation or cover:

One of the key differences between an indoor and outdoor extension cord is the lack of thick insulation on the indoor extension cord. 

Since the cord indoors is not susceptible to harsh environmental conditions – therefore, they are designed with thin insulation to reduce cost. If they are used on the outside, their insulation will not be strong enough to handle the moisture, heat and temperature.

Lack of protection from Fire Hazard:

Since outdoor extension cords are more exposed to harsh environmental conditions, they use three-pronged cords with grounding that helps minimize fire or shock hazard if the insulation gets damaged. 

This makes them safe for running heavy power consuming devices which would not be possible with indoor extension cables without running the risk of melting the insulation.

Can you use an indoor extension cord on a covered porch?

Indoor extension cords are strictly for use indoors only and since they lack the proper protection for use outdoors, using them on your covered porch would leave you open to significant risks. 

However, if you use the indoor extension cord by following safety precautions well, you may use them on your covered porch for a day or two at most.

Can indoor extension cords get wet?

Indoor extension cords can get wet but they can be used with proper precaution after they are dried. 

If the plug became wet, it would become problematic if you tried to use it since water in contact with exposed wire with electric supply can pose serious danger such as electrocution or even fire hazard.

A wet extension cord could deliver painful shock to the person touching it if the voltage is low, however if the voltage is high, the damage could be lethal. Another issue could be plugging in a wet extension cord which may result in a short circuit and end up causing an electrical fire.

What kind of extension cords can be used outside?

Although there are many extension cords available in the market, some of them work the best for outdoor use. The Iron Forge Cable is one of them, being a multi-purpose cord – they can be used both indoors and outdoors. 

Another great choice is the Otimo Outdoor Extra Heavy Duty Extension Cord which can also be used both indoors and outdoors. They are around 100 feet long in length, thus it can be used to cover a long distance outside your house.

Last but not the least, SIMBR is yet another cord suitable for both indoor and outdoor uses which consists of a three-pronged cord that can handle up to 15 amps – it is also 50 feet long so you can cover a considerable amount of ground outdoors as well.

How do you tell if an extension cord can be used outside?

There are several signs and indicators that help us identify extension cords suitable for outdoor use. Some of those indicators are stated below:

Designated Letter:

Extension cords often have scribbles printed on their bodies that indicate many of its details. One such indicator represents whether the cord is suitable for use outdoors – if the letter “W” is present on either the cord package or the cord body, then that cord is suitable for use outdoors.

Type of plug:

Outdoor cords often come with grounding, thus they have a three-pronged plug whereas indoor extension cords have two-pronged plugs. This difference makes the outdoor cord less vulnerable to shock or fire hazard.

Insulation thickness:

Another key feature to identify whether an extension cord is suitable for outside use is by its insulation thickness. 

The thick and sturdy insulation of the extension cord is meant to protect the cord from the harsh sunlight, high temperatures and moisture present outside – indoor cords would not need such protection.

What is the difference between an indoor and outdoor extension cord?

There are some key differences that separate an indoor extension cord from its outdoor counterpart. Those differences are described below:

Insulation Thickness:

The environmental conditions indoors drastically vary from outdoors since the temperature outside is higher, there is a presence of sunlight and usually there is higher moisture outside.

Extension cords used outside need to have sufficient protection from all these environmental conditions – thus their manufacturers design them with thick insulation.

However, indoor extension cords do not require such protection thus their insulation is much thinner and more vulnerable to damage.

Gauge Differences:

The gauge of a wire determines how much current a wire can conduct and is usually identified by the cord’s thickness. 

Since outdoor cords are usually longer in length, they need to be wider in diameter to balance out the heat produced by the resistance in the wire which makes outdoor extension cords have lower gauge ratings.

On the other hand, indoor extension cords are shorter in length and for this reason – they tend to be thinner in diameter and thus have a higher wire gauge rating.

3-prong vs 2-prong plugs:

Outdoor cords require grounding to mitigate shock and fire hazard, thus they come with 3-prong plugs whereas indoor cords are less exposed to harsh environments and therefore grounding is not added to their plugs. 

Final thoughts

Using an indoor extension cable outside is highly risky, and leaving them outside for longer than a day is not recommended. Since indoor extension cables are not designed for outdoor usage, they will break down over time when exposed to harsh environments, posing a fire or shock hazard to your home.