Stillwater · Ordovician Volcanics · Wales / Snowdonia (Blaenau Ffestiniog uplands)

Llynoedd Cwn

A dark upland lake set in a grassy hollow with rocky outcrops, overlooked by distant Snowdonia mountain ridges under a blue sky.

Llynnau'r Cwn is really three pools, not one lake, and it pays to know which is which before you start walking the bank.

Fair · Trout
Marabou Damsel · 8-12
Fairlive now
Good drifting conditions on Llynoedd Cwn
Good wave on — drift country. A useful wave. Work the productive shore.
63% confidence

Llynoedd Cwn is often best in spring through autumn.

What moved it
  • WindN 6 km/hLight breeze
Today's fly
Marabou Damsel
Marabou Damsel8-12
Retrieve, sub-surface
Conditions on the water
Live gauge
Wind
Light breeze
N 6 km/h
N
N
from the north
WaveRipple
Water temp—
Air temp11°C
CloudClear
Pressure1021 hPa
Rain · recent0.0 mm

Some readings unavailable — check directly before fishing.

How to fish it · for Trout
When
June–August; best on overcast, breezy days
Where
Set up a broadside drift and cover the water systematically. Work a bushy searching pattern on the bob and drop a contrasting nymph on the point.
The plan
Plan A

Set up a broadside drift and cover the water systematically. Work a bushy searching pattern on the bob and drop a contrasting nymph on the point.

Plan B

If the main plan is not working, switch to a smaller, more imitative pattern fished slower and deeper. A change of drift angle can also make a difference.

Watch for

Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.

Bank

Bank-only venue. Fish from accessible margins, points, weed edges, and inflows.

Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 3 with Pro.

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Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Daddy Long LegsHatch
2
3
2
Murrough (Great Red Sedge)Hatch
2
3
2
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2
Lake OliveHatch
1
2
2
2
2
2
1

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Trout fly box
Bays & launches · 1
Day ticket via Cambrian Angling AssociationAccess varies
Three-pool moorland group (Llynnau'r Cwn); the top pool is peaty and presumed fishless, but the lower two hold wild brown trout to around 1½lb.
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What's coming
Plan ahead
5-day outlook
Condition match
66%
Cloud25%
Wind100%
Temp60%

A reasonable day here, though cloud isn't quite in the sweet spot.

Other water nearby · 5
Llyn Llagi
1.0 km
Brown trout
Llyn yr Adar
1.0 km
Brown trout
Llyn Conglog
2.0 km
Brown trout
Llyn Cwm Corsiog
2.0 km
Brown trout
Llyn Cwm Foel
2.0 km
Brown trout
Gallery · 2
  1. A dark upland lake set in a grassy hollow with rocky outcrops, overlooked by distant Snowdonia mountain ridges under a blue sky.
    Uppermost lake on Llynnau'r Cwn
  2. Terrain map of the venue
    Terrain map
About this water

Llynnau'r Cwn is really three pools, not one lake, and it pays to know which is which before you start walking the bank. The top pool is peaty, dark, and presumed fishless — nobody bothers with it, and neither should you. The lower two are a different matter, holding wild brown trout to around a pound and a half and fishing considerably better for the fact that most visitors never get past the first pool to find out. Worth the extra fifteen minutes to reach the water that actually holds fish, and worth remembering which pool is which on the way back.

  • Lake
  • Ordovician volcanics
Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Lake Olive is in its seasonal window, boosting the chance of targeted feeding.
Related guides
Scotland Playbookloch & river fishingThermal Layers & Troutreading depth and temperatureEuro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts