Christmas well and truly arrived in our house this week! Apparently the 1st of December was National Christmas Tree Day as well as National Christmas Lights Day – Makes sense seeing as you tend to put them up at the same time!

Which is rather fitting as my family and I also go out on the 1st December and choose our Christmas tree – We like to get a real one, and my eldest boy loves to pick it out.

So our tree stood in our living room all of Sunday and by Monday afternoon it was really crying out to be decorated. I found a Christmas playlist on Spotify (‘Christmas is Coming’ – Check it out, you won’t be disappointed) and fought the knot of tree lights to get them on the tree and twinkling.

But as soon as I turned them on, Buble started buffering and it made me remember an article from last year that said how Christmas tree lights could affect your Wi-Fi!

I think in my case it had less to do with the tree lights, and more to do with the fact that I had 3 devices running off my router – My phone playing Spotify through my Bluetooth speaker, my laptop on in the corner of the room, and my smart tv turning the screen into a log fireplace through Amazon Prime Video. Festive? Yes! Wi-Fi consuming? Oh yes!

This potential issue with Christmas lights pops up every year though and it’s worth mentioning again just to prevent any interference happening. No one wants to choose between functioning Wi-Fi and a Christmassy home do they!

So, could Christmas tree lights really affect my Wi-Fi? Here’s the science bit…

Christmas lights emit a very weak electromagnetic field which can theoretically interfere with the radio waves being transmitted from your router, thus affecting your Wi-Fi speed. If the lights were to transmit electromagnetic radiation at or around the same frequency, then yes, they could slow down your Wi-Fi.

Between the LED or lamp being completely on or off, it can exhibit negative resistance which in turn causes radio energy. This happens less with modern day lights than older ones though (see below for more info on this).

Is your tree lit up to give a soft glow, or does it look like something fresh out of Blackpool illuminations? The more lights you have, the stronger the electromagnetic field will be.

And closer the router is to the lights, the higher the chance of interference.

Here are our top tips to stay festively connected…


Rule #1 – Don’t place things on top of your router

Just don’t do it. This doesn’t just go for decorations, but in general.

Don’t put Christmas lights or anything else directly on top of, or too close to, your router. I can’t personally see the appeal of adorning it with twinkly lights or putting decorations on top of it but each to their own.

While it has been reported that routers that were placed too close to Christmas tree lights could be negatively affected by signal interference, if they’re not directly next to each other or on top of each other, it should be fine.


Rule #2 – Use a main plug socket

Christmas is one of those times of year when you’re struggling for socket space and digging out all the extension cables you can find to be able to power Christmas tree lights and all kinds of other lit decorations.

But don’t be tempted to unplug the router and plug it into the extension. It will work a lot better, and faster, if it’s plugged into a main socket.


Rule #3 – The more modern the lights, the better

There are generally 2 types of light whose qualities have the potential to cause interference.

Older types of Christmas lights that are arranged in a string of low voltage lamps in series with each other and are designed to blink can cause radio interference which can lead to dips in Wi-Fi speed.

More modern Christmas lights use solid-state LED’s and have an external control for flashing which don’t create radio noise. However, it’s worth noting that some LED’s have a chip inside the bulb to control the blink and these devices can also cause interfence.

On the whole though, modern lights are definitely less likely to cause you a Wi-Fi problem, so maybe save yourself the annual horror of trying to untangle your 10 year old string of lights and treat yourself to some new ones.


Rule #4 – Don’t put your router in ‘high traffic’ areas

Tis the season for family gatherings, friend get-togethers and all sorts of festive shenanigans. Not to mention the big man in red tumbling down the chimney! Humans are great signal absorbers, so put the router in a place where it won’t get blocked by partying people or round bellies that shake like jelly.


If you’re Wi-Fi geeks like us, and your tree isn’t up yet, why not do a little experiment? Test your Wi-Fi and download speeds before and after putting up the Christmas tree with the lights turned on. We’re pretty sure the results will be rather negligible – But let us know your results!