Short answer: Most robot mowers are built to handle rain and say so with a water-resistance rating, and many pause or go home when a rain sensor trips. A rating does not mean you should mow in a storm. In winter, most people stop mowing when the grass stops growing and store the mower as the maker describes, so check the manual.

Figures in this article come from our catalog of 378 robot lawn mowers (data as of 2026-10-07). They are what the makers claim.

Can a robot mower be left out in the rain?

Many makers design the mower body to sit outside in normal weather. The dock (the charging station) is also made for outdoor use, though its rating can be lower than the mower's. Our catalog does not record whether a model has a rain sensor, so we cannot give a count. Many models do. The idea is simple: when the sensor detects rain, the mower can stop and return to the dock, then try again later. Check the manual to see what your model does and how it can be set.

Whether you leave the mower out all season, or keep it in a garage and set it out only for mowing, is something to settle with the maker's guidance.

What do IPX4, IPX5, and IPX6 mean?

IP stands for "ingress protection". It is a standard code for how well a product keeps out water and dust. An "X" means the item was not rated for dust. The number after it is the water part:

  • IPX4: protected against splashing water from any direction. Think of light rain or a spray.
  • IPX5: protected against water jets. Think of a garden hose pointed at it.
  • IPX6: protected against powerful water jets. This is a higher bar than IPX5.

With "IP66", the first 6 means the product is dust-tight, and the second 6 is the same powerful-jets level as IPX6.

These ratings come from lab tests of the sealed product. They say how well the case handles water from outside. They do not say the mower will cut well in a storm, and they do not cover things like deep puddles or long submersion. Always read how the maker defines the rating and what it covers.

What ratings do makers claim?

In our data, 278 models list an IP rating:

Rating claimed Models
IPX6 139
IPX5 80
IP66 35
IPX4 18
IPX6 for the mower, IPX4 for the station 4
Mixed ratings (mower IPX5, charger IPX2, power supply IP67) 2

So IPX6 and IPX5 are the most common, and IP66 is also seen. Pay attention to the last two rows. The mower, the dock, and the power supply can have different ratings. If a model lists a lower rating for the dock or charger, ask where the maker says to put it and whether it should be sheltered.

Should I let it mow in the rain?

Even with a good rating, there are good reasons to avoid it.

  • Wet grass cuts worse. Blades can tear and clump wet grass instead of cutting it cleanly, and clippings can stick under the deck.
  • Wheels slip more. Wet ground gives less grip, which matters on hills. See robot mowers for slopes and hills.
  • Ruts and marks. Soft, wet soil can show wheel tracks, especially at turns.
  • Dirt and mud gets onto the mower and the dock contacts, which means more cleaning.

A rain sensor or a schedule that skips wet days helps with many of these. If your model lets you pause for rain for a set time, that can protect the lawn as well as the mower. Follow the maker on storms, lightning, flooded areas, and snow. When in doubt, bring it inside.

Can a robot mower run at night?

Many models can run on a schedule at any hour, and some people set them to mow overnight to keep the lawn free in the day. Check these things first:

  • Noise. Among the 258 models with a claimed noise level, the middle claim is 59 dB, and claims run from 52 to 80 dB. You may still hear it at night near an open window. Check any local noise rules too.
  • Small animals. Garden animals can be more active after dark. Makers often have safety advice for pets and wildlife in the manual. Read it and decide for yourself. See our safety article for kids and pets.
  • Camera models. Some mowers use cameras to see their surroundings, and low light can limit them. Ask the maker how the model handles darkness.

What do I do with the mower in winter?

In places with cold winters, the grass stops growing, and mowing is no longer needed. Here are the common steps. Your manual has the exact version for your model, so check the manual for the details.

  1. Stop mowing when growth stops. Many people switch off the schedule.
  2. Clean the mower. Remove grass and dirt from the deck, wheels, and blade area. Follow the manual on how, and be careful around the blades. See the maintenance checklist.
  3. Care for the battery. Makers often have advice on charge level before long storage, and on temperature limits. Follow it. Do not leave a battery empty for months unless the maker says so.
  4. Store it as the maker says. Many makers say to store the mower indoors in a dry place that stays above freezing. Others allow the dock to stay outside. The manual decides.
  5. Dock and power supply. If you store the mower indoors, think about whether to lift the dock and the power supply, too, or protect them from snow and ice.
  6. Spring start. Check the blades and the battery, give the mower a clean, and restart the schedule as the grass starts to grow.

If your mower can be set to a winter mode or a "do not mow" period, the app or the manual will say how.

What if I live in the southern hemisphere?

The seasons are reversed. In places like Australia, New Zealand, or southern Africa, winter falls roughly in June to August, so the slow season for grass comes in the middle of the year, and the busy mowing season comes around December to February. In warm regions the grass may never stop growing. The rules are the same: mow when the grass grows, rest when it does not, and follow the maker for storage and temperature limits.

What this means for you

  • A rating like IPX6 is a good sign for outdoor use, not a license to mow in storms.
  • Let the lawn dry before mowing when you can, especially on slopes.
  • At the end of the season, clean, charge as the maker says, and store as the manual says.
  • Check the manual for temperature limits for charging and storage.

Quick answers

Does IPX6 mean a mower is waterproof? No. It means protection against powerful water jets in a test. It is not the same as waterproof or submersible.

Is IPX5 enough for normal rain? Makers rate their mowers for outdoor use. Your manual will say what weather is fine for your model.

Can I leave the mower outside all winter? Only if the maker says so. Many tell you to store it indoors.

Should I mow wet grass? It is usually harder on cutting quality and on hills. Follow the maker's advice and the rain settings in the app.

Next step

Still choosing a model? The quiz can help you match a mower to your yard and climate. For the care steps, see the maintenance checklist.