Stillwater · Ordovician Volcanics · Wales / Snowdonia (Nantlle Ridge)

Llyn Cwm Silyn

A dark corrie lake at Cwm Silyn with the crags of Craig yr Ogof rising behind it, Snowdonia.
Fair · Trout
Diawl Bach · 12-14
Fairlive now
Good drifting conditions on Llyn Cwm Silyn
Good wave on — drift country. A useful wave. Work the productive shore.
52% confidence
What moved it
  • WindN 9 km/hLight breeze
Today's fly
Diawl Bach
Diawl Bach12-14
Washing-line, sub-surface
Conditions on the water
Live gauge
Wind
Light breeze
N 9 km/h
N
N
from the north
WaveRipple
Water temp—
Air temp12°C
CloudBroken
Pressure1023 hPa
Rain · recent0.0 mm

Some readings unavailable — check directly before fishing.

How to fish it · for Trout
When
The buzzer is on. Murrough may also come into play as the day warms. The ripple is helpful — fish should move onto the feed and a slow-drifted team or single wet will cover water well.
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.

Boat — drift

A gentle ripple is ideal for drifting — broadside drift covering the wind lanes should be productive.

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 5 with Pro.

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Through the year
0–3 scale · July 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
Gammarus Scud (Olive)
Gammarus Scud (Olive)
10-14 · Gammarus Scud
Washing-line, sub-surface
Bays & launches · 1
Day ticket via Fishing PassportAccess varies
Remote glacial cwm under the Nantlle Ridge — wild brown trout with a relict Arctic char (torgoch) population.
What's coming
Plan ahead
5-day outlook
Condition match
88%
Cloud100%
Wind100%
Temp60%

Conditions are ideal for Llyn Cwm Silyn — wind, cloud and temperature all line up.

Other water nearby · 5
Llyn Nantlle
2.0 km
Brown trout · Sea trout
Llyn y Dywarchen
5.0 km
Brown trout · Rainbow trout
Llyn Cwellyn
6.0 km
Brown trout · Arctic char · Salmon
Llyn Cwmystradllyn
8.0 km
Brown trout · Rainbow trout
Llyn Cwm Dwythwch
9.0 km
Brown trout
Gallery · 2
  1. A dark corrie lake at Cwm Silyn with the crags of Craig yr Ogof rising behind it, Snowdonia.
    One of the twin corrie lakes at Cwm Silyn, beneath Craig yr Ogof in Snowdonia, north Wales.
  2. Terrain map of the venue
    Terrain map
Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Cloud cover (cloud) suits the fishery well.
  • Buzzer is in its seasonal window, boosting the chance of targeted feeding.
Related guides
Scotland Playbookloch & river fishingThermal Layers & Troutreading depth and temperatureEuro Nymphingsubsurface methods
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