Storm Éowyn and the Limits of Your Phone Signal

Storm Éowyn arrived on 24 January 2025 and set a record: a gust of 114 mph measured at Mace Head in Ireland, the strongest recorded there. Power went out for well over a million homes and businesses across Ireland and Northern Ireland, and for many of them it stayed out for days. What made the storm significant beyond the immediate damage was the regulator's assessment of what happened to mobile phone networks. Ofcom described a rapid, severe and sustained decline in mobile performance affecting all operators — degradation, it said, on a scale that had not been seen before. If your emergency plan assumes you will be able to make a phone call, this is the event that ought to change it.

Why Signal Goes First

The reason is not damage to masts. It is power. A mobile site is an electrical installation like any other, and when the local network goes down it runs on whatever battery it has. Ofcom's resilience work has found that only around a fifth of UK mobile sites have radio access network battery backup that lasts beyond roughly fifteen minutes, and only about five per cent can ride out a six-hour loss of mains power. Core network sites are much better protected, but the mast serving your street generally is not. This inverts the intuition most people hold. Signal does not degrade slowly over a long outage; it tends to disappear in the first hour, while your phone is still at 90 per cent and you are still calm.

The Second Problem: Everyone Calls at Once

Even where masts stay up, capacity does not. A major incident produces an enormous simultaneous spike as everyone in the area calls family at the same moment, and a voice call is the most expensive thing a network can carry — it holds a two-way channel open for its entire duration. Texts behave completely differently. A text is a tiny packet the network can queue, prioritise and retry on its own, which is why messages frequently arrive when calls will not connect. If you need to reach someone in an affected area, send a short text and wait, rather than ringing repeatedly. Repeated ringing is also part of the problem you are experiencing.

What Actually Keeps Working

Broadcast radio. This is not nostalgia, it is a different architecture. One transmitter with serious backup power covers an enormous area, and a receiver needs nothing from any network — no SIM, no authentication, no data path. During Éowyn, as during Storm Arwen in 2021 and the Iberian blackout in 2025, radio was the channel that continued to carry usable local information about restoration times, water distribution and rest centres. A wind-up or battery set with a USB output costs very little and doubles as a phone charger and a light. Buy one before you need one, and write your local BBC and commercial frequencies on a piece of tape stuck to the case, because tuning by guesswork in the dark is miserable.

Emergency Alerts: Useful, But Not Universal

The UK's Emergency Alerts system broadcasts to mobile phones in a defined area, and its second nationwide test ran on 7 September 2025. It was used for real in January 2026, reaching around 500,000 people in Cornwall and the Isles of Scilly. It is genuinely valuable and you should make sure it is enabled. But it has boundaries that official messaging tends to gloss over. It relies on a cell broadcast standard supported by most 4G and 5G handsets — it will not reach 2G-only or older feature phones, which are disproportionately used by exactly the older and lower-income households most exposed in an emergency. It cannot reach a phone in airplane mode or with alerts switched off. And it depends on a functioning mast, which brings us back to the battery problem. Enable it, then plan as if it might not arrive.

Power Banks Matter Even With No Signal

It is tempting to think that if the network is down, a charged phone is pointless. It is not. Your phone is still the torch you will actually use, the camera for insurance photographs of any damage, the place your saved documents and PDFs live, and the device that will reconnect the instant a mast comes back — at which point you want battery left to send the messages you have queued. Two power banks, kept charged, is the right answer for most households: one in the house and one in a bag. A larger portable power station is worth it if someone in the home depends on mains-powered medical equipment, but it is an upgrade, not the starting point.

The Landline Question

If you still have a traditional copper line, a plain corded handset generally keeps working during a power cut, because the line is powered from the exchange rather than from your house. That is a genuinely useful fallback and worth keeping one cheap handset for. If you have already moved to digital voice over fibre or broadband, it is gone: the router needs mains power and its battery, where there is one, is measured in tens of minutes. The UK's migration away from copper is steadily removing this layer of resilience from the average home, which is a reason to take the radio and the power banks more seriously rather than less.

The Paper Card

Write these on one card and put it somewhere fixed — a kitchen drawer, the back of a cupboard door. 999 for emergencies. 105, free from any UK phone, for a power cut, which routes you to the right network operator without you needing to know who that is. 0800 111 999 for a suspected gas leak. Your water company's emergency number. Your energy supplier. Two personal contacts, including one who lives well outside your area, because in a regional event the out-of-area relative becomes the hub everyone can try to reach. None of this works if it only exists in a contacts app on a phone you cannot unlock.

A Plan That Does Not Need the Network

The last piece is agreement rather than equipment. Decide in advance where your household will meet if you cannot contact each other, what time you will each try to check in — a fixed hour is better than continuous attempts — and who the designated out-of-area contact is. Tell that person they have the job. Make sure children know it, and that schools and carers have the same information. This costs one conversation and removes the single worst experience of a comms failure, which is not lacking information about the storm. It is not knowing where the people you love are.

The Wider Point

Éowyn demonstrated that a serious storm now produces two overlapping failures: the power cut everyone plans for, and the communications collapse that follows it within the hour and that almost nobody plans for. The regulator's own figures say the mast network cannot ride out a multi-hour outage, and the fixed-line fallback is being retired. The correct response at household level is not to buy anything exotic. It is a radio that works without a network, batteries for the phone, numbers on paper, and one agreed plan. Assume the signal goes early and you will be right far more often than you are wrong.