When you install festoon lights outside, you're not just creating atmosphere—you're introducing electricity into the unpredictable UK weather. That means safety needs to come first. With the right precautions, your lights can shine bright through every season without risk to your home, family, or garden guests.

This guide covers everything you need to know about outdoor festoon light safety in the UK, from plug placement and weatherproofing to fire prevention and best-practice maintenance.

Do Outdoor Festoon Lights Need an RCD?

Yes—an RCD (Residual Current Device) is absolutely essential for any outdoor electrical setup. It's your first line of defence against electric shock.

If moisture causes a fault, an RCD will shut off power instantly—potentially saving lives. For permanent outdoor sockets, look for one with a built-in 30mA RCD. If you're plugging into an indoor socket and running a cable outdoors (not recommended), use an RCD-protected plug or adapter.

Top Tip: Always test the RCD using the "Test" button before plugging in your lights. If it doesn't trip, don’t use the socket.

Are Festoon Lights Safe in the Rain?

Only if they’re designed to be. Not all festoon lights are waterproof—so check the IP rating.

For British weather, look for:

• IP44: Splash-proof. Safe under cover (like gazebos or verandas).

• IP65 or higher: Fully rainproof. Ideal for exposed areas.

Avoid using indoor lights outdoors, even temporarily. Rain and condensation can corrode sockets, trigger faults, or cause electrical shorts.

Tip: Secure all plugs and connections off the ground and under a waterproof enclosure. Damp grass or puddles and electricity do not mix.

Can Festoon Lights Catch Fire?

Low-voltage LED festoon lights are incredibly safe when used properly—but yes, poor installation or neglect can lead to fire hazards.

Common fire risks include:

• Overloaded circuits

• Covered bulbs overheating under fabric or foliage

• Frayed or damaged cables

• Incompatible extension leads

Safety Tips:

• Always use LED bulbs—they generate minimal heat.

• Don’t bury cables under rugs, cushions, or garden features.

• Replace any cracked or scorched sockets immediately.

How to Protect Outdoor Plugs from Weather

Outdoor plugs are the most vulnerable point in your lighting setup. Even if your lights are waterproof, one exposed plug can ruin everything.

Here’s how to protect them:

• Use an IP66-rated outdoor socket box with a hinged cover.

• If you're using an extension lead, place connections inside a weatherproof connector box.

• Elevate all plug points off the ground to avoid water pooling.

Pro Tip: Wrap a drip loop—create a small dip in the cable just before it enters the socket box. That way, rainwater drips off rather than following the cable inside.

What Are the Best Extension Leads for Outdoor Festoon Lights?

Never use an indoor extension lead outdoors. It’s not just risky—it’s dangerous.

Instead, choose:

• Outdoor-rated extension leads with IP54 or IP66 protection.

• Fully unwound cables to prevent heat buildup.

• Leads with a thick rubber casing to handle rough surfaces and moisture.

Avoid coiling the cable while it’s in use—it can cause overheating. Always fully unwind and route away from paths where it can trip people or get damaged.

What’s the Maximum Load for Festoon Light Circuits?

Every festoon light set has a maximum wattage and current rating. Exceed it, and you risk overheating the cable, damaging the sockets, or tripping your circuit.

Let’s break it down:

• Standard UK plug sockets support up to 13 amps (roughly 3,000 watts).

• But festoon lights usually run on much less—especially LED types.

• If daisy-chaining multiple strings, total their combined wattage.

Tip: Check the manufacturer’s max connection guide—most allow up to 5-10 sets in a chain depending on the design.

How to Keep Cables Safe and Tidy

Loose or trailing cables are not only unsightly—they're a hazard.

Keep things safe by:

• Routing cables high up or along fences to avoid tripping.

• Using cable clips or ties to secure lines.

• Avoiding pinching cables in doors, gates, or under heavy objects.

Never run cables across walkways without proper cable covers. Pets and children can trip—and repeated foot traffic will eventually damage the wire insulation.

Are Solar Festoon Lights Safer?

Yes—and no. Solar festoon lights run at low voltage (typically 1.2–3.7V), making them very safe from an electrical standpoint. There’s no risk of shock, and they don’t need plug sockets.

However, safety still matters:

• Make sure the solar panel is properly mounted and won’t fall.

• Use lights with a good IP rating, especially for the battery housing.

• Avoid placing wires where they can be chewed or pulled.

Best Use: Solar festoon lights are ideal for low-risk areas like fences, garden edges, or around seating where people won’t interact with the wires often.

Can You Leave Outdoor Lights on Overnight?

Yes, but only if they are:

• Designed for outdoor use

• Installed safely with proper waterproofing and circuit protection

• Not left near flammable materials

Timers or smart plugs are a great idea. They let you set automatic shut-offs, saving energy and avoiding overnight risks.

Fire Safety Tip: Avoid wrapping festoon lights around flammable decorations (like fabric bunting or dry plants). Even LEDs can get warm after hours of use.

How to Handle Damaged Festoon Lights

Stop using them immediately. Damaged insulation, exposed wires, or flickering bulbs can all be signs of internal faults.

Steps to follow:

1. Unplug or isolate the power.

2. Inspect the damage—look for cuts, frays, or water ingress.

3. Replace damaged sections rather than trying to repair them with tape.

4. Contact the manufacturer for spare parts or replacements if needed.

Never try to DIY a broken light string unless the design specifically allows for safe replacement. Most sealed IP-rated lights should not be opened.

How Often Should You Check Your Outdoor Lighting?

Every season—or monthly if lights are used daily. Regular inspection prevents small problems from turning into big hazards.

Your safety checklist:

• Are all cables intact and firmly clipped?

• Are bulbs clean and seated properly?

• Are plugs and sockets dry and secure?

• Are RCDs working correctly (test button)?

Also check after storms or extreme temperatures—UK winters can wreak havoc on plastic fittings and seals.

What Kind of Bulbs Are Safest for Festoon Lights?

Always use LED bulbs designed for festoon fittings. They’re:

• Low voltage and cool to the touch

• Shatter-resistant (many use polycarbonate lenses)

• More energy-efficient and longer lasting

Avoid old-fashioned filament bulbs. They get hot, use more energy, and can become fire hazards if covered or touching flammable materials.

Tip: Choose dimmable LEDs if you're pairing your lights with a smart system or dimmer switch.

Final Safety Tips for Peace of Mind

• Buy from trusted UK suppliers with clear safety ratings (UKCA/CE marked)

• Follow the manufacturer's installation guide to the letter

• Don’t take shortcuts with electrics—when in doubt, get professional help

• Keep children and pets away from wiring

• Use timers or smart plugs for extra control

Creating a magical outdoor space shouldn't come at the cost of safety. With the right approach, your festoon lights can light up your evenings while keeping your home, family, and guests protected.

Want the charm without the worry? Prioritise weatherproofing, circuit protection, and seasonal inspections—and enjoy glowing nights, year-round.