Llyn Celyn northern uplands up Carnedd y Filiast (Snowdonia): route map, distance and time
669 m · Snowdonia
Carnedd y Filiast is a 669 m Hewitt, Nuttall and Marilyn on the moorland north-east of the Arenig hills, a remote summit above Llyn Celyn.
A hard mountain walk to the summit from Llyn Celyn north-shore public track.
Llyn Celyn northern uplands starts at about 325 m and gains 432 m over 5.6 km to 660 m on the track. The first 4 km are the easy part, averaging 4%. The steepest kilometre is the one ending at 5 km, which climbs 143 m at an average of 14%. The final 0.6 km eases to the top.
Llyn Celyn northern uplands at a glance
| Distance | 5.6 km one way, to the top |
|---|---|
| Ascent | 440 m |
| Climb on the track | 432 m up, 98 m down on the way |
| Start and top of the track | 325 m to 660 m (summit 669 m) |
| Steepest 500 m | About 17%, from 4.6 km |
| Steeper than 1 in 5 | 4% of the way |
| Time up | 1h 50m by Naismith's rule |
| There and back | 3h 0m, down the same way |
| Grade | Hard |
| Start | Llyn Celyn north-shore public track |
| Start grid reference | SH 861 410 |
| Summit grid reference | SH 871 445 |
| Parking | No checked car park for this start; find lawful parking nearby |
Llyn Celyn northern uplands 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 Llyn Celyn northern uplands 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.
Llyn Celyn northern uplands 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 | 433 m | +108 m | 11% | SH 857 416 |
| 2 km | 494 m | +61 m | 6% | SH 862 424 |
| 3 km | 529 m | +35 m | 4% | SH 869 426 |
| 4 km | 473 m | -57 m | -6% | SH 875 432 |
| 5 km | 616 m | +143 m | 14% | SH 872 440 |
| 5.6 km | 660 m | +44 m | 8% | SH 871 445 |
How long Llyn Celyn northern uplands takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 1h 30m | 2h 25m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 1h 50m | 3h 0m |
| Relaxed 4 km/h, 12 min per 100 m up | 2h 15m | 3h 40m |
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 07:05, sunset 16:51. Start by 12:51 to be down before dark, allowing 3h 0m for the walk and an hour for stops.
- Tomorrow: sunrise 07:06, sunset 16:49. Start by 12:49 to be down before dark, allowing 3h 0m for the walk and an hour for stops.
Carnedd y Filiast summit weather for this route
-
Poor Today Wednesday 28 October
Slight rain, up to 10°C at the summit, feeling as cold as 1°C, summit wind 42 mph gusting 53 mph, 100% chance of rain. Rated Poor. Sunrise 07:05, sunset 16:51.
-
Marginal Tomorrow Thursday 29 October
Mostly dry, up to 10°C at the summit, feeling as cold as 2°C, summit wind 32 mph gusting 40 mph, 8% chance of rain. Rated Marginal. Sunrise 07:06, sunset 16:49.
Best day of the next seven for Llyn Celyn northern uplands: Saturday 31 October, with summit gusts around 11 mph and a 2% chance of rain.
Cloud inversion tomorrow morning: 57% (Good), best around 05:00.
Hour-by-hour Carnedd y Filiast forecast
Before you go, also check: MWIS Snowdonia forecast · Met Office mountain forecast.
What to take today
- A warm layer, hat and gloves: it feels like 1°C on top.
- Waterproof jacket and overtrousers: 100% chance of rain.
- A windproof layer, and poles for balance in gusts to 53 mph.
- 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 Carnedd y Filiast
Carnedd y Filiast is a 669 m Hewitt, Nuttall and Marilyn on the moorland north-east of the Arenig hills, a remote summit above Llyn Celyn. More about Carnedd y Filiast, with the live forecast.
On the lists: Hewitt, Nuttall, Marilyn.
Extend the walk: tops near the summit
- Waun Garnedd-y-Filiast (651 m), 0.7 km north
- Carnedd Llechwedd-llyfn (644 m), 1.3 km west
Challenges that include Carnedd y Filiast
More walks from Llyn Celyn north-shore public track
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- Llyn Celyn northern uplands up Carnedd Llechwedd-llyfn
- Llyn Celyn via Carnedd y Filiast up Waun Garnedd-y-Filiast
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 861 410, the summit at SH 871 445), 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.
Llyn Celyn northern uplands: questions and answers
How far is Llyn Celyn northern uplands?
Llyn Celyn northern uplands is 5.6 km one way to the summit of Carnedd y Filiast, with 440 m of ascent. There and back by the same way is about 11.2 km.
How long does Llyn Celyn northern uplands take?
About 1h 50m to the summit of Carnedd y Filiast and 3h 0m 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 40m for the round trip.
How steep is Llyn Celyn northern uplands?
The steepest 500 m averages about 17%, starting 4.6 km from the start, and 4% of the way is steeper than 1 in 5. Llyn Celyn northern uplands climbs 432 m in all on the track.
Where do you park for Llyn Celyn northern uplands?
Llyn Celyn northern uplands starts from Llyn Celyn north-shore public track. The grid reference is SH 861 410. No checked car park for this start; find lawful parking nearby
Is Llyn Celyn northern uplands suitable for beginners?
Not as a first mountain. Peakify grades it Hard: steep, rough ground where a slip matters. Build up on an easier route first.
What time should I start Llyn Celyn northern uplands today?
By 12:51 at the latest. Sunset on Carnedd y Filiast today is 16:51, Llyn Celyn northern uplands takes about 3h 0m there and back, and that leaves an hour for stops. Start earlier in winter or if the forecast turns.
Is there a GPX for Llyn Celyn northern uplands?
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.