Is It Okay If A Lawn Mower Is Left Out In The Rain?

Many of us have, at one time, finished mowing the lawn and forgot to put the lawn mower away. Then it rained for three days straight. When we return to our trusty machine, we wonder: Was it okay that I left my lawn mower out in the rain, or is it ruined?

Whether you have a push mower or a riding lawn mower, leaving it out in the rain is going to have a certain effect. What matters is how long you leave it exposed and what kind of mower you have. Electric mowers are probably the most vulnerable, as water can cause them to short circuit and damage the batteries. While gas-powered lawn mowers have a little more tolerance for getting wet,  they are nevertheless susceptible to being damaged by the elements.

The biggest threat is water entering the fuel system. If you get rain in your lawn mower engine, that water can contaminate the fuel and lead to internal rusting. Water can also enter the fuel through cracked hoses and fuel lines. If the moisture comes into the carburetor, which is what mixes the fuel and air together to create combustion, it can damage the component and cause the engine to stall. Water can also clog up the air filter and gum up spark plugs.

It's important to note, however, that your lawn mower isn't going to die if you've left it out in the rain once or twice. The real threat would be continually exposing it to rain. Lawn mowers are water resistant, to an extent, but not waterproof. Rust is another concern, as any metal that is exposed to water long enough will begin to take damage. External rust can be just as damaging as internal.  Rusty mower decks can fall apart, and rusty blades can seize and stall the engine. 

This is why it's best practice to store your mower indoors, though this isn't always easy. One of the biggest issues owning a lawn mower is that they are fairly large machines that require a good space like a shed to store properly. If you have neither a shed nor a garage, you can get away with covering your mower with a tarp, but this will not help protect it from consistent rain. Another type of backyard storage, such as a lean-to, would be better if your space is limited. 

So, yes, you can leave your mower out in the rain. A few days won't kill it. However, don't make a habit of keeping it out there long term. You'll likely be shopping for a brand new lawn mower. If you are in the market, check out the lawn mower buying guide for every type of lawn.