Plas y Brenin up Moel Siabod: route map, distance and time
872 m · Snowdonia
Moel Siabod is the solitary mountain above Capel Curig, climbed by the rocky Daear Ddu ridge past Llyn y Foel or a simple path from Plas y Brenin.
A path through woodland and up the north-east slopes to the summit.
Plas y Brenin starts at about 190 m and gains 658 m over 3.5 km to 846 m on the track. It is steep from the start: the first kilometre climbs 164 m (16%). The steepest kilometre is the one ending at 3 km, which climbs 243 m at an average of 24%. It keeps climbing at 13% to the top. About 46% of the way is steeper than 1 in 5, so expect hands-on-knees going and a slow descent.
Plas y Brenin at a glance
| Distance | 3.5 km one way, to the top |
|---|---|
| Ascent | 690 m |
| Climb on the track | 658 m up, 0 m down on the way |
| Start and top of the track | 190 m to 849 m (summit 872 m) |
| Steepest 500 m | About 26%, from 2.2 km |
| Steeper than 1 in 5 | 46% of the way |
| Time up | 1h 50m by Naismith's rule |
| There and back | 2h 35m, down the same way |
| Grade | Moderate |
| Start | Plas y Brenin footpath by Afon Mymbyr |
| Start grid reference | SH 716 577 |
| Summit grid reference | SH 705 546 |
| Parking | No checked car park for this start; find lawful parking nearby |
Plas y Brenin map
The track from the start (green) to the summit (blue), with a marker at each kilometre.
Height profile and getting to the start
Near the start
From OpenStreetMap, within 2 km. Check opening times before you rely on them.
Download the Plas y Brenin GPX
Ascent only: plan your way down. A planning track, not checked on the ground; it doesn't show safe scrambling moves. Track data © OpenStreetMap contributors (ODbL), heights from a terrain model.
Plas y Brenin kilometre by kilometre
Height, climb and average gradient for each kilometre of the track, with a grid reference at the end of each one to check your position on the map.
| At | Height | Climb | Gradient | Grid ref |
|---|---|---|---|---|
| 1 km | 354 m | +164 m | 16% | SH 714 568 |
| 2 km | 533 m | +179 m | 18% | SH 711 559 |
| 3 km | 776 m | +243 m | 24% steep | SH 707 550 |
| 3.5 km | 846 m | +70 m | 13% | SH 705 546 |
How long Plas y Brenin takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 1h 30m | 2h 5m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 1h 50m | 2h 35m |
| Relaxed 4 km/h, 12 min per 100 m up | 2h 15m | 3h 10m |
Times leave out stops. Coming down the same way, the table counts the ascent once; steep descents on rough ground can be as slow as the climb.
- Today: sunrise 07:47, sunset 18:14. Start by 14:39 to be down before dark, allowing 2h 35m for the walk and an hour for stops.
- Tomorrow: sunrise 07:49, sunset 18:11. Start by 14:36 to be down before dark, allowing 2h 35m for the walk and an hour for stops.
Moel Siabod summit weather for this route
-
Good Today Sunday 18 October
Overcast, up to 6°C at the summit, feeling as cold as -4°C, summit wind 23 mph gusting 29 mph, 0% chance of rain. Rated Good. Sunrise 07:47, sunset 18:14.
-
Marginal Tomorrow Monday 19 October
Dense drizzle, up to 7°C at the summit, feeling as cold as -2°C, summit wind 38 mph gusting 48 mph, 53% chance of rain. Rated Marginal. Sunrise 07:49, sunset 18:11.
Best day of the next seven for Plas y Brenin: Sunday 18 October, with summit gusts around 29 mph and a 0% chance of rain.
Cloud inversion tomorrow morning: 0% (Low), best around 04:00. 7-day inversion outlook.
Hour-by-hour Moel Siabod forecast · 14-day forecast · Is it safe to climb Moel Siabod?
Before you go, also check: MWIS Snowdonia forecast · Met Office mountain forecast.
What to take today
- An insulated jacket, hat and warm gloves: it feels like -4°C on top.
- A waterproof jacket. It can rain on the tops in any forecast.
- Microspikes for icy paths. In snow, an ice axe and crampons and the skills to use them.
- Map and compass, and the skills to use them. A phone is a backup, not a plan.
- A head torch, food, water, a charged phone and a small first aid kit.
About Moel Siabod
Moel Siabod is the solitary mountain above Capel Curig, climbed by the rocky Daear Ddu ridge past Llyn y Foel or a simple path from Plas y Brenin. More about Moel Siabod, with the live forecast.
On the lists: Hewitt, Nuttall, Marilyn.
Challenges that include Moel Siabod
More walks from Plas y Brenin footpath by Afon Mymbyr
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- Eastern Glyderau from Capel Curig up Gallt yr Ogof
- Eastern Glyderau from Capel Curig up Y Foel Goch
Other routes up Moel Siabod
| Route | Distance | Ascent | Time up | Grade |
|---|---|---|---|---|
| North-east approach from Pont Cyfyng | 4.1 km one way | 700 m | 2h 0m | Hard |
| Western approach from Pen-y-Gwryd | 5.2 km one way | 600 m | 2h 0m | Hard |
| Pont Cyfyng via Llyn y Foel and Daear Ddu | 4.7 km one way | 740 m | 2h 10m | Scramble |
| Daear Ddu from Dolwyddelan | 6.2 km one way | 740 m | 2h 30m | Scramble |
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 716 577, the summit at SH 705 546), what happened and how many are in your group. If you have no signal for a call, a text to 999 works once you have registered your phone with emergencySMS: text "register" to 999 before you go.
Plas y Brenin: questions and answers
How far is Plas y Brenin?
Plas y Brenin is 3.5 km one way to the summit of Moel Siabod, with 690 m of ascent. There and back by the same way is about 7.0 km.
How long does Plas y Brenin take?
About 1h 50m to the summit of Moel Siabod and 2h 35m there and back by Naismith's rule (5 km/h plus 10 minutes per 100 m of ascent), before stops. A relaxed group takes nearer 3h 10m for the round trip.
How steep is Plas y Brenin?
The steepest 500 m averages about 26%, starting 2.2 km from the start, and 46% of the way is steeper than 1 in 5. Plas y Brenin climbs 658 m in all on the track.
Where do you park for Plas y Brenin?
Plas y Brenin starts from Plas y Brenin footpath by Afon Mymbyr. The grid reference is SH 716 577. No checked car park for this start; find lawful parking nearby
Is Plas y Brenin suitable for beginners?
Yes, for fit walkers on a clear day. Peakify grades it Moderate: a long climb on a made path, but the top is high, exposed and colder than the start. Turn back if the cloud comes down and you can't navigate.
What time should I start Plas y Brenin today?
By 14:39 at the latest. Sunset on Moel Siabod today is 18:14, Plas y Brenin takes about 2h 35m there and back, and that leaves an hour for stops. Start earlier in winter or if the forecast turns.
Is there a GPX for Plas y Brenin?
Yes. Download it from this page. It is an ascent-only planning track from the start to the summit, plotted on OpenStreetMap paths and not checked on the ground.