Can robot mowers work in the rain?

What IPX ratings mean for a robot mower

The IP code is an international standard for how well an enclosure keeps out solids and water. The X means the solids part was not rated, and the number after it covers water. Robot mowers commonly carry IPX4, IPX5 or IPX6, and the listing or manual states which.

A higher number means more protection from water from outside, but none of these ratings means you can submerge the mower or blast it with a pressure washer. Always clean in the way the manual describes. For example, the Ecovacs Goat O1000 RTK is listed as IPX6; other models list lower ratings or none, so check before assuming you can hose it down.

Rain sensors, weather timers and rain delay

Many robot mowers have a rain sensor on the body or use weather data through the app. When rain is detected, the mower can return to the dock and wait for a set delay before starting again. Some models also adjust how long they run to the speed of grass growth, such as the weather timer listed for the Husqvarna Automower 315, which reduces needless running in cool, wet spells.

Settings differ by brand, so look in the manual or app for rain delay, sensitivity and whether the mower should mow in light rain. On flat, free draining lawns some owners let the mower run in drizzle. On clay, slopes or new turf, pausing in rain usually gives a better lawn and fewer stuck messages.

1. 1

   Find the rain sensor or rain delay setting in the app or menu.

2. 2

   Choose whether to pause in all rain or only heavy rain.

3. 3

   Set a delay so the grass can dry a little before restarting.

4. 4

   Check the sensor is clean; a film of dirt can confuse it.

Cutting wet grass: what changes

Wet grass is heavier and bends rather than standing up to be cut, so the finish can be less even. Clippings stick together and build up under the deck and round the blade disc, which slows the blades and can trigger faults. Wheels lose grip on slopes and leave tracks on soft ground. The RHS advises avoiding mowing when the lawn is very wet, and the same logic applies to robots, even though their cuts are small.

Little and often helps here. Because a robot takes only the tips, clippings are fine and disappear into the lawn more readily than a weekly cut would. Keep the height a little higher in wet spells, and remember the one-third rule if the lawn has grown long during a rainy fortnight; the one-third rule tool works out safe steps. If slopes and wet ground are causing trouble, read robot mower keeps getting stuck.

Covers, shelters and thunderstorms

Robot mowers do not need a rain cover to work, but a ventilated shelter over the dock keeps off sun and debris and can stop the top cover filling with leaves. Avoid tarps and tight covers, which trap heat and moisture and can block sensors. Our robot mower garage guide covers clearances and airflow.

Thunderstorms are a different matter. Many makers advise disconnecting the charging station's power supply and sometimes the boundary wire during thunderstorms, because a long wire loop can pick up surges. Follow your manual's advice; some systems include protection, but the details vary.

Note:Before cleaning, press the stop button and switch the mower off or disable it with the PIN. Wear gloves near the blades and never lift a running robot. Unplug the dock before touching it in wet weather, keep the power supply and socket dry, and use an RCD protected outdoor socket. Never pressure wash or submerge a mower unless the manual says it is safe.

A cleaning schedule for a wet UK summer

In a damp season, clippings build up faster, and a clogged mower cuts poorly and works harder. A short routine every week or two keeps it running. Use a soft brush and a wooden or plastic scraper, and wipe the contacts dry so the mower charges reliably.

If you are choosing a mower and expect a lot of wet weather, look for a clear IPX rating, rain detection and a slope rating with margin. Our best robot lawn mower guide lists the rating where the maker gives one, and the wire-free guide covers RTK and vision models.

• Weekly in wet spells: brush the underside, disc and wheels
• Every week or two: wipe the charging contacts on mower and dock
• Every few weeks: check and replace blades
• After storms: check the dock, power supply and wire connections
• End of season: clean, charge and store indoors as the manual advises

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Frequently asked questions

Are lawn mowers waterproof? Not in the sense of being safe under water. Robot mowers are water resistant to the level of their IPX rating, which covers rain and splashes or jets. Corded and cordless push mowers usually have no such rating and should not be used in rain.

Do I need a robot lawn mower cover? No. The mower and dock are built to sit out in rain. A ventilated garage over the dock is an optional extra for shade and debris, not a rain cover.

Can I hose down my robot mower? Only if the manual allows it. Some models permit a gentle rinse; many say to use a brush and damp cloth only. Never use a pressure washer unless the maker says it is safe.

Should my robot mower run in the rain? It can, but pausing in heavy rain usually gives a cleaner cut and protects soft lawns and slopes. Use the rain sensor or rain delay if your model has one.