The difference between an indoor and an outdoor Christmas light set is written on the box as an IP rating. IP44 handles splashes and light rain, IP65 handles a hose and a real downpour, and IP67 survives being submerged for a short time. Anything with no rating at all is an indoor set, and putting it outside is how a display dies in week two.
This guide explains what the two digits mean, which rating suits each part of a display, and what actually goes wrong when an indoor set spends an Australian December outside.
What the two numbers mean
IP stands for Ingress Protection. It is a standard code, and the two digits are separate ratings that always appear in the same order.
The first digit is solids, from dust and grit up to fingers. For Christmas lights the meaningful values are:
- 5 — dust protected. Some dust may get in but not enough to matter.
- 6 — dust tight. Nothing gets in.
The second digit is water. This is the one that matters outdoors:
- 0 — no protection at all.
- 4 — splashing water from any direction. Light rain, spray off a path.
- 5 — a low pressure jet from any direction. Heavy rain, a hose.
- 6 — a powerful jet. Driving storm rain.
- 7 — temporary immersion, typically 30 minutes under 1 metre of water.
So IP44 is "splash resistant from any direction". IP65 is "dust tight and hose proof". IP67 is "dust tight and survives being briefly underwater".
An X in either position, as in IPX4, means that part was not tested. IPX4 tells you about water and nothing about dust.
What rating you need, by where the lights go
Indoors, on a tree or a mantel. No rating needed. An indoor set is cheaper and usually has a thinner, more flexible cable that is easier to weave into branches.
Under cover outdoors: a verandah, a carport, a covered patio. IP44 is enough. The lights get humidity and the occasional wind-blown splash, not direct rain.
Exposed outdoors: gutter line, fence, an open tree, a garden bed. IP44 is the practical minimum and IP65 is what you want. The gap between them is the difference between coping with a shower and coping with a summer thunderstorm.
Ground level, where water pools. IP65 at least. Rain running down a driveway or a garden bed after a storm sits around a cable for hours.
In or beside water: a pond edge, a pool surround, a fountain. IP67. Anything less does not belong near a pool.
Most listings in the Christmas lights and outdoor decorations range state the intended use, but very few state an IP rating, so ask us if a rating matters for your site. Read the listing before the ladder comes out, not after.
What the rating does not cover
This is where most people get caught. An IP rating usually applies to the light string itself, not to the plug, the controller, the battery box or the join between two sets.
A set rated IP44 along its length can still have a controller box that must stay dry, and the plug where two sets meet is almost never rated at all. That join is the single most common failure point in an outdoor display.
The fix is not a better set, it is better placement:
- Keep every plug and controller off the ground.
- Make a drip loop, so the cable hangs below the connection and comes back up. Water runs to the bottom of the loop and falls off rather than tracking into the plug.
- Put the join inside a weatherproof connection box, or at least somewhere sheltered and facing down.
- Use an outdoor-rated extension lead, which has thicker UV-stable insulation than an indoor one.
There is a fuller guide on hanging outdoor Christmas lights safely that covers clips, ladders and RCD protection.
Why indoor lights fail outside here, specifically
Two Australian conditions do the damage, and neither is rain.
Ultraviolet light. Summer UV is strong and it breaks down unprotected PVC cable. An indoor cable left in the sun for six weeks goes chalky, then brittle, then cracks. The cracks let water in at the worst possible place, which is anywhere along the run rather than at a join you thought about.
Heat cycling. A cable on a colorbond roof or a north-facing brick wall can reach well above air temperature during the day and drop twenty degrees overnight. Everything expands and contracts, seals loosen, and moisture gets pulled into sockets as they cool. Outdoor-rated sets are built with this in mind. Indoor ones are not.
The result is rarely a bang. It is a set that works fine for three weeks and then has a dead section, and by then it is mid December and the shops are picked over.
Sets built for the weather
A few examples of what an outdoor-ready set looks like in practice.
Icicle sets take the most weather because they hang from the gutter, right where the water runs. A 32M icicle set with 960 LEDs covers a full house frontage in one run, and this one is solar powered with its own panel, so there is no mains plug at all. Fewer joins means fewer unrated plugs hanging in the rain.
Rope light is the most physically robust format. The LEDs sit inside a solid extruded tube rather than in individual sockets, so there is far less to get into. A 30M rope light set suits fence lines, railings and anywhere the cable gets handled.
Solar removes the mains question entirely. A 32M solar icicle set has no lead running back to the house, so there is no extension join sitting outside at all. The panel needs genuine direct sun to charge, and run time after dark depends on that day's charge, so solar suits a fence or a hedge better than the one display everyone is looking at.
Buying checklist
- Decide where each set is going before you buy anything.
- Under cover, IP44 is enough. Exposed, look for IP65. Near water, IP67.
- Measure the run and buy a set long enough to avoid extra joins.
- Assume the plugs are not rated, and plan somewhere dry and off the ground for them.
- Use an outdoor extension lead and an RCD-protected outlet.
- Keep the packaging until the set has survived its first real storm.
For year-round lighting there are separate pages for ceiling and pendant lights, and for floor and table lamps.
There is also a short page of solar fairy lights and sensor night lights.
Frequently asked questions
What does an IP rating on Christmas lights mean?
IP stands for Ingress Protection, and the two digits are separate ratings: the first for solids such as dust and the second for water. IP44 is splash resistant from any direction, IP65 is dust tight and hose proof, and IP67 is dust tight and survives being briefly underwater. An X in either position, as in IPX4, means that part was not tested.
What IP rating do I need for outdoor Christmas lights?
Indoors, on a tree or a mantel, no rating is needed. Under cover outdoors, such as a verandah or carport, IP44 is enough. Exposed outdoors, IP44 is the practical minimum and IP65 is what you want. At ground level where water pools you need IP65 at least, and in or beside water, such as a pond edge or pool surround, you need IP67.
Does the IP rating cover the plug and the controller?
Usually not. An IP rating generally applies to the light string itself, not to the plug, the controller, the battery box or the join between two sets, and that join is the single most common failure point in an outdoor display. Keep every plug and controller off the ground, make a drip loop, and put the join inside a weatherproof connection box or somewhere sheltered and facing down.
Why do indoor lights fail outside in an Australian summer?
Two conditions do the damage, and neither is rain. Summer UV breaks down unprotected PVC cable, so an indoor cable left in the sun goes chalky, then brittle, then cracks. Heat cycling also loosens seals and pulls moisture into sockets as they cool. Outdoor-rated sets are built with this in mind and indoor ones are not.
Are solar Christmas lights a good option?
Solar removes the mains question entirely, because a solar set has no lead running back to the house and so no extension join sitting outside. The panel needs genuine direct sun to charge, and run time after dark depends on that day's charge, so solar suits a fence or a hedge better than the one display everyone is looking at.
The full range is in Christmas lights and the wider Christmas range. Delivered Australia-wide in 3 to 5 business days, with 30-day returns on eligible items (see our return policy).