Can you run a generator in the rain?

What the safety agencies and makers say

Source	What it says
OSHA	"Keep a generator dry; do not use it in the rain or wet conditions. If needed, protect a generator with a canopy."
Ready.gov	"Keep the generator dry and protected from rain or flooding. Touching a wet generator or devices connected to one can cause electrical shock."
CPSC	"Follow manufacturer instructions to reduce shock hazards during wet weather."
Generac	"Never run a generator directly in the rain, snow or other wet conditions."
Honda	Using a generator in rain or snow, or with wet hands, "could result in electrocution. Keep the generator dry."
Champion (manual)	"Do not operate or store the generator in rain, snow, or wet weather."

They all agree on the goal: keep the generator dry. Where they differ is how. OSHA allows a canopy. Champion's help center goes further and describes a cover made for running generators in bad weather.

The danger is electric shock. Water and a running generator's outlets, cords and plugs don't mix.

How to run a generator in wet weather

If the power is out and it's raining, here's how to stay within that advice.

1. Keep it outdoors and 20+ feet from the house. CPSC, NFPA and Ready.gov all give 20 feet. Rain doesn't change that.
2. Cover it from above, open on the sides. Use an open canopy, as OSHA describes, or a cover made for running generators. Don't wrap it.
3. Keep clear space around it. Champion's help center says the generator should be on a flat, level surface in an open area, away from windows and doors, with "at least a five-foot radius of clearance all around it."
4. Put it on dry, raised, level ground. Stay out of puddles and low spots where water collects.
5. Keep the vents open. Honda says to keep all cooling holes "open and clear of debris, mud, water."
6. Use GFCI protection. OSHA says to use GFCIs, especially in wet or damp areas. Champion's manual says the same for damp areas.
7. Use outdoor-rated cords in good condition. NFPA says to check cords for cuts and tears and make sure the plug has all three prongs.
8. Dry your hands first. OSHA says never to handle a generator's electrical parts if you're wet or standing in water.

Generator covers and tents

Covers made for running generators exist, and at least one maker points to them. Champion's help center says that with advance notice, you can put a severe weather cover over a generator "to prevent severe weather like rain or snow from affecting your unit while in operation outside."

Champion also answers a common worry: will the cover trap exhaust and trigger the CO shut-off? Its answer is that, "when properly installed," the cover won't cause the generator to shut off from elevated CO.

What to look for, and what to avoid:

• Made for a running generator, and sized for your model. Follow its install steps exactly.
• Open around the exhaust and the cooling vents.
• Not a tarp thrown over the top. A cover that touches a hot muffler can melt or catch fire. Honda warns that a hot engine and exhaust "can ignite or melt some materials."
• Not an enclosure. Honda says "do not enclose the generator in any structure." Champion says not to contain generators during operation.

Never move it inside to keep it dry

This is the deadly mistake. When rain starts, people pull the generator into the garage, under the porch, or into a shed. CPSC says never to use a portable generator inside homes, garages, basements, crawlspaces or sheds, "even if doors or windows are open."

Also avoid:

• Covered porches, carports and decks. Exhaust can collect there and drift inside.
• Under eaves right against the wall. That breaks the 20-foot rule.
• The back of a truck or SUV. Champion's manual says never to start or run a generator there.

If you can't keep it dry outdoors, don't run it. A battery power station can cover small loads indoors with no exhaust: see portable power station vs generator.

Starting it, refueling and shutting it down in the rain

• Start it under its cover, with nothing plugged in. Then plug in loads one at a time.
• Refuel only when it's off and cool, with the cover keeping rain out of the tank. NFPA says never refuel while hot.
• Plug and unplug with dry hands, and keep plug connections off the wet ground.

What about snow?

Generac's advice covers snow too: never run a generator directly in snow. Keep snow off the generator and away from its vents and exhaust. Clear around it, under the cover, as the snow builds up.

After the storm: was it rained on?

Honda says that if a generator is stored outdoors without protection from the weather, you should check all the electrical parts on the control panel before each use. Moisture or ice "can cause a malfunction or short circuit" that could electrocute you.

OSHA adds: don't use electrical equipment that has been under water. It must be dried out and properly checked first.

If your generator was flooded or soaked, don't start it. Have a servicing dealer inspect it.

Run it outdoors only, 20+ feet from the house, away from windows and doors: generator carbon monoxide safety.