Why your WiFi drops out at night

If your WiFi is fine all day and falls apart around 8pm, it's not broken — it's congested. After dark two things peak at once: everyone in your house is home streaming, and every neighbour's WiFi is hammering the same few channels yours uses. Daytime has spare air. The evening doesn't. That's why a fault report to your provider goes nowhere — there's no fault to find. The good news is congestion is fixable, mostly for free, by changing where your router sits and which slice of the airwaves it uses. Here's what's happening and the order to fix it.

The pattern that gives it away

Congestion has a fingerprint. It's fine in the morning, fine mid-afternoon, then video calls stutter and streams buffer between roughly 7 and 11pm, and it clears by bedtime. If that's your pattern, stop looking for a hardware fault. A genuinely faulty modem or a bad cable drops out at random, all day. A congestion problem keeps office hours in reverse.

What's actually happening after dark

Two separate slowdowns hide behind "WiFi's bad at night," and people constantly confuse them.

1. WiFi congestion — in your home and your street. Remember that WiFi is one conversation at a time: every device on a channel takes turns, and only one can talk at any instant. In the evening, every device in your house is awake and busy. Worse, WiFi doesn't stop at your walls. Your neighbours' networks reach into your home, and they're all crowding onto the same handful of channels. In a unit block or a tight street, you're not sharing the air with your ten devices — you're sharing it with two hundred. That's the shouting match, and it's loudest at peak.

2. NBN evening congestion — your provider's problem. Separately, some providers don't buy enough wholesale capacity (called CVC, the bandwidth they purchase to carry their customers) for peak hour, so everyone on that provider in your area slows down together around dinnertime. This one isn't WiFi at all — it shows up even on a cabled connection.

Telling them apart is one test, below. Get that right before you spend money, because the fixes are completely different.

The one test that tells you which it is

Plug a laptop straight into the modem with a network cable and run a speed test during the bad window. Then unplug and test again over WiFi from the same spot.

Cabled is fine, WiFi is bad → it's WiFi congestion. The fixes below are yours, and they're mostly free.
Cabled is also slow at night → it's NBN evening congestion. No WiFi tweak helps. That's a conversation with your provider, or a switch to one that doesn't choke at peak.

Don't skip this. Half the people who buy a mesh system to fix nightly dropouts had an NBN congestion problem the whole time, and the new gear changed nothing.

If it's WiFi congestion: the fixes, in order

Work down this list and stop when the evenings settle.

Lock your 2.4GHz channel. 2.4GHz has only three channels that don't overlap: 1, 6 and 11. By default many routers "auto" their way onto a crowded one, or worse, sit between two and clash with both. Set it manually to whichever of 1, 6 or 11 is least busy on your street (a free WiFi analyser app on your phone shows you). And don't run 2.4GHz at a wide 40MHz channel — on a congested band it just collides with more neighbours. Keep it at 20MHz.
Push everything onto 5GHz. 5GHz doesn't travel as far between homes, which is exactly why it stays cleaner at peak — your neighbours' 5GHz barely reaches you. Get every phone, laptop and TV that can run on 5GHz onto it, and leave 2.4GHz for the gear that genuinely needs the range. If your router lumps both bands under one name and you can't tell what's connecting where, splitting them into two names gives you control.
Place the router properly. Central, up high, out of the media cabinet, away from the TV and the microwave (a microwave genuinely jams 2.4GHz while it runs). A router fighting congestion from inside a timber cabinet in the corner is starting the evening on the back foot.
Get the chatty smart gear out of the way. Those cheap plugs and old cameras camp on 2.4GHz and chatter constantly, eating airtime the whole street is already fighting over. Moving them onto their own lane frees room for the things you actually care about — see how to put your smart devices on their own WiFi.

What about a new router or mesh?

If you've done the above and the evenings still bite, then it's worth looking at hardware — but for the right reason. A better router with newer WiFi handles a crowded band more gracefully and shares airtime more fairly between devices. Mesh helps by spreading your load across more radios so each one referees fewer devices. But buy it knowing it's a congestion-management upgrade, not a magic fix. On a genuinely jammed channel, even good gear has to wait its turn. Sort the channel and placement first; they're free and they do most of the work.

Common questions

Why does my WiFi drop out at night but not during the day?

Because two things peak after dark: everyone in your house is home streaming at once, and every neighbour's WiFi is busy on the same handful of channels. Daytime has spare airtime; 8pm does not. If your dropouts cluster in the evening, that is congestion, not a fault, and no fault report to your provider will fix it.

Is slow WiFi at night a problem with my internet plan?

Sometimes, but usually no. There are two separate evening slowdowns. One is WiFi congestion in your home and street, which a faster plan does nothing for. The other is NBN evening congestion, where your provider has not bought enough capacity for peak hour — that one shows up even on a cabled connection. Test on a network cable: if cabled is fine and WiFi is bad, it is WiFi, not the plan.

How do I fix WiFi congestion at night?

Lock your 2.4GHz band to channel 1, 6 or 11 and avoid silly-wide channel widths, push everything that can run on 5GHz onto 5GHz, and place the router central and high rather than in a cabinet. On a crowded street those three changes settle most evening dropouts without spending a cent.

Why is 2.4GHz WiFi worse at night?

2.4GHz travels furthest and through walls, so it reaches from your neighbours' homes into yours, and there are only three non-overlapping channels for everyone to share. In the evening every household's devices are awake on that same crowded band, so it becomes a shouting match. 5GHz does not travel as far between homes, so it stays much cleaner at peak.

Will rebooting my router fix nightly dropouts?

It can help temporarily — a reboot often makes the router pick a clearer channel and clears a full connection table. But if it comes back every evening, rebooting is treating the symptom. The lasting fix is setting the channel manually, splitting the bands, and placing the router well so it is not fighting congestion from a bad position.

The bottom line

Nightly dropouts are almost always congestion, not a fault. Run the cable test to rule out NBN peak-hour congestion, then lock your channel, push devices to 5GHz, place the router well, and get the smart-home clutter off your main band. That sequence settles most homes for free. Nightly dropouts are usually the first symptom of a network that's quietly run out of room — the bigger picture is in why a house full of devices keeps dropping out.

Run the test, tried the fixes, and 8pm still kills your WiFi? Then it's worth a proper look — congestion mapping, the right channels, gear sized to your street. We'll tell you whether it's your setup or your provider, and fix what's actually fixable. Tell us when it drops out.