What Happens If You Leave Your Lawn Mower In The Rain?

Lawn mowers are durable bits of machinery, built to handle whatever tough mowing job you throw at them. However, there is one thing they are not designed to handle: A relentless downpour. Leaving your lawn mower exposed to rain is never a good thing, and while a brief, light shower might not cause massive irreversible damage, prolonged and repeated exposure is almost guaranteed to lead to expensive problems, like fuel system damage or electrical system issues. Let's take a look at exactly what happens when you leave your mower out in the rain.

The specific risks depend on what type of mower you use. For gas-powered models, the engine and fuel system are the most vulnerable, as water can easily contaminate gas and engine oil. This can lead to your mower malfunctioning or even dying outright. On the other hand, electric and battery-powered mowers face a different (but equally serious) threat. We all know that water and electricity are a dangerous combo; even a little bit of moisture can cause the battery to corrode, rendering it useless. And regardless of what type of mower you have, the metal components are all susceptible to rust, which will slowly but surely eat away at your mower's frame and overall integrity, and you will be stuck paying for another one (whether or not it is the best time of year to buy a new lawn mower).

When rain hits your mower, it can cause a cascade of problems, with rust and corrosion being the most visible. The mower deck, blades, and various cables are all made of metal, making them the perfect targets for rust. And this goes beyond just looks; rust weakens the structure of the metal in the mower and makes it less efficient (and prone to breaking) over time. 

For gas-powered mowers, the issues run much deeper. Water can seep into a gas mower's fuel tank, causing the gas to separate, which then leads to poor performance or not starting again at all. What's worse is that water can also contaminate engine oil and turn it into a milky, ineffective lubricant that causes friction in your engine and can even make it seize. The air filter is another huge component at risk. When it gets wet, it can become clogged and limit the air flow an engine needs to run properly. This is yet another issue that can cause the mower to run roughly, lose power, or stall out entirely.

For electric mowers, the main concern is (you guessed it) the electrical system. Moisture causes short circuits, which can permanently damage your mower's motor or its internal battery components. That, in turn, almost always requires either pricey professional repairs or a full replacement. And even if maintenance is one of the things you considered before buying an electric lawn mower, unexpected repairs or replacements are still very frustrating. So while a single rainstorm might not ruin your mower, all of the varying effects of water damage can significantly shorten its lifespan and turn into a major headache.

If you did happen to accidentally leave your mower outside during a rainstorm, do not try to start it up immediately. Instead, get it moved to an area that is covered and dry, like your garage or a shed, and let it air dry for at least 24 hours. You can speed up this process by tagging in a fan or leaf blower to help dry the exterior. Once your mower is dry, perform a quick inspection. First, check the air filter; if it is damp, remove it and replace it with a new one. For a gas mower, check the oil dipstick; if the oil looks milky, it is a sign of water contamination, and you should get the oil changed by a professional as soon as possible. Finally, look for any signs of rust on the deck and blades, and clean them thoroughly to prevent any further corrosion.

The best way to deal with rain damage on your mower is to prevent it from happening in the first place. We know accidents happen, and that it is easy to get sidetracked with another project, but try to ensure you have a ready lawn mower storage solution that is covered and dry, for when rain starts. This can be a shed, a garage, or even under a high-quality waterproof cover or tarp. Taking these simple proactive steps can save you from a lot of headaches and costly repairs.