The short answer
Outdoor Christmas lights are safe to run through rain and snow when the lights and cords are rated for outdoor use, every outdoor connection is plugged into a GFCI-protected outlet, and the plug connections are kept up off the ground and away from water. Most problems come from the in-between parts: indoor cords used outside, connections sitting in a puddle, too many strings on one outlet, and damaged cords nobody checked.
The tips below follow the Electrical Safety Authority, Ontario's electrical safety authority, and Health Canada.
Start with the right lights and cords
Light strings and lighted decorations are rated for either indoor or outdoor use, and indoor-rated products belong indoors. Check the box or the label before anything goes on the house:
- Outdoor rating: the lights, the extension cords and any timer you use outside should all be rated for outdoor use.
- Certification mark: the ESA advises choosing lights with a recognized Canadian approval mark from an accredited agency. Health Canada gives CSA, cUL and cETL as examples.
- Where you buy: the ESA suggests buying electrical products from trusted retailers, and notes that typos in the product information can be a sign of a counterfeit. If a product has no certification mark, don't use it.
- Recalls: Health Canada suggests checking the Recalls and Safety Alerts database before you buy or use seasonal lights.
Check every string before it goes up
Lights that spent a year in a box can be damaged in ways that are easy to miss. Plug each string in on the ground first and look it over:
- Throw out any string or cord that is frayed, has exposed wires or has loose connections, as Health Canada advises.
- Replace broken or burned-out bulbs, and replace damaged plugs.
- Never remove the third prong (the grounding pin) from a plug. The ESA notes it's there to prevent electric shock.
- Read the package instructions and don't go over the wattage limits they give.
Rain and wet weather
Outdoor-rated lights are made to handle rain on the strings themselves. The weak spots are the plug connections, where one string or cord joins the next, and the outlet. The ESA advises keeping connections off the ground and away from puddles, driveways and walkways.
- Lift every connection off the ground. Clip it to the house, a railing or a stake rather than letting it sit on the lawn or in a garden bed where water pools.
- Plug outdoor lights into an outlet with GFCI protection. The ESA recommends using GFCIs for outdoor connections.
- Don't run cords through windows or doors, where they get pinched every time the door closes. The ESA lists this along with running cords under carpets.
- Keep connections clear of downspouts and the drip line of the roof, where water falls in a steady stream.
Why outdoor lights trip the GFCI when it rains
A GFCI (ground fault circuit interrupter) shuts off power when it detects current leaking out of the circuit, which is exactly what can happen when water gets into a connection. The Electrical Safety Foundation International describes ground faults as usually happening when equipment is damaged or its parts get wet, so current escapes the circuit. So a GFCI that trips after rain is usually doing its job.
If yours keeps tripping:
- Unplug the lights, let the connections dry, then reset the GFCI.
- Plug the strings back in one at a time. The one that trips the outlet is the one with the wet or damaged connection or cord.
- Raise or cover that connection, or replace the string if the cord is damaged.
- Never fix it by plugging the lights into an outlet without GFCI protection, or by resetting it over and over while everything is still wet.
The ESFI also recommends testing GFCIs every month. Press the test button, check the power cuts off, then press reset.
If breakers or fuses keep tripping too, the ESA treats that as a warning sign that cords or circuits are overloaded.
Extension cords and outlets
Too many decorations on one cord or circuit can overheat and cause a fire, the ESA warns, so spread them out:
- Don't plug too many lights or decorations into one outlet.
- Follow the manufacturer's instructions and connect no more than three light strings together, as the ESA advises. On a long roofline, that means planning a few shorter runs back to your power source.
- Use an outdoor-rated extension cord that's long enough to reach without joining several cords end to end.
- Keep bulbs away from cords, wires, cloth, paper and anything else that can burn.
If you're working out how much roofline you have to cover before buying cords and strings, our guide on how to measure your roofline walks through it.
Snow, ice and winter storms
Snow on outdoor-rated lights isn't a problem on its own. What causes trouble in a GTA winter is what happens around the lights:
- Don't chip ice off lights or cords with a shovel, scraper or anything sharp. You can cut the insulation without noticing.
- Keep cords and connections out of the paths you shovel and the areas a snowplow or snowblower will throw snow, which is another reason the ESA says to keep connections away from driveways and walkways.
- After a storm or a freeze-thaw, walk around the house and look for strings that have pulled loose, sagging runs and cords pinched under ice.
- If a section is damaged, unplug the lights before you touch it.
Ladders and the roofline
For many people the ladder is the riskiest part of the job. Before you climb:
- Look for overhead power lines before using a ladder or decorating outdoor trees, and stay at least 3 metres away, as the ESA advises.
- Set the base 1 ft out from the wall for every 4 ft of height, and extend the ladder at least 1 m (3 ft) past the edge you're leaning it on, following CCOHS ladder guidance.
- Keep three points of contact, don't work from the top three rungs, and move the ladder instead of overreaching.
- Don't set a ladder on ice, mud or other slippery ground. Where electricity is a hazard, CCOHS says to use a fibreglass ladder.
- Hang lights with proper clips. The ESA warns that staples and nails can damage cords.
If the ladder work is the part you'd rather skip, our guide to hiring a pro or doing it yourself covers what each involves.
Can you leave outdoor Christmas lights on overnight?
The ESA's advice is to turn off holiday lights and decorations when you leave the house or go to bed, and Health Canada says the same. The easy way to do that every night is an outdoor-rated timer, or the schedule in a smart plug or light app, set to switch the lights off at bedtime.
A timer also keeps your power bill in check. Our guide to what it costs to run Christmas lights in Ontario shows how the hours you leave them on add up.
Seasonal lights come down in January
The ESA advises removing holiday decorations after the season, because they aren't meant for year-round use. Leaving seasonal strings and clips up through the rest of the winter and into spring means more time in ice, sun and wind than they were made for.
Permanent roofline lighting is a different kind of product, built to stay up all year. The permanent lights we install are low-voltage 24V, UL listed and IP67 sealed against rain and snow, in a track mounted along the roofline. See permanent Christmas lights if you'd rather not put lights up and take them down every year.
Let us handle it
Home Guardians installs Christmas lights across Vaughan, Maple, Woodbridge, Kleinburg, Concord and Thornhill, plus Richmond Hill, King City and nearby areas. Seasonal installation covers the install, mid-season fixes if a strand goes out, January takedown and off-season storage, with a lifetime warranty on the lights we supply.
Year one starts at $8 per linear foot for warm or cool white and $11 for RGB, with the lights included and yours to keep. Following years are half the year-one price ($200 minimum). See the Christmas light installation page for the full service, or use the instant price tool: enter your address and it measures your roofline on the map and shows a year-one estimate right away. The final price is confirmed with a free measurement before any work starts, and taxes are extra.
Install slots fill up by mid-November, so it's worth booking early.