Mobile phone reception varies greatly on Snowdon (Yr Wyddfa), and it’s important to appreciate that a mobile signal cannot be relied on. Also, remember that cold conditions considerably reduce normal battery life so it’s quite a good idea to take a spare power pack too.
Reception is best on the Llanberis Path because it can pick up the transmitter in Llanberis, and there is a good 4G signal at the summit.
Signal is intermittent on the Pyg Track and Miners’ Track, and there is currently none at Pen y Pass. (Although a mast has recently been erected at Pen y Pass, it is not functional yet, and anyway will initially only be for the rescue services and EE users.)
The Rhyd Ddu Path and Snowdon Ranger Path have recently benefitted greatly from a new mast at Rhyd Ddu which is now available to all mobile users (not just EE). This has considerably improved communications on the west side of the mountain and in the Rhyd Ddu and Snowdon Ranger car parks.
The worst signal is on the south-east side of the mountain, notably affecting the Watkin Path, which for the most part has no signal whatsoever, including at the car park.
On the mountain, where the signal is not good enough to make a phone call, a text or WhatsApp message will often not take too long to get through.
If you need to ring 999 but there’s no signal, if you have previously registered with emergencySMS (to register just text REGISTER to 999) you can send an SMS text message to 999. This message will often get out when reception isn’t good enough to allow a voice call. If you use this service, then in your text you should include which service you want (probably Mountain Rescue), what the problem is, and where exactly you are.
The only car parks that currently have a phone signal are in Llanberis, Rhyd Ddu and Snowdon Ranger. The car park at Pen y Pass, whilst it has no signal, has free WiFi near the building.
If you are planning on phoning for a taxi or arranging to meet others, you should bear the above in mind.