Stillwater · Ordovician Volcanics · Wales / Snowdonia (Glyderau)

Llyn Idwal

Llyn Idwal, a glacial lake in Cwm Idwal, Snowdonia, with still water reflecting the surrounding mountains.

Idwal is a Ramsar-designated cirque lake in Cwm Idwal NNR — eleven hectares of clear water at three hundred and seventy-three metres, beneath Y Garn and Glyder Fawr, with the Devil's Kitchen scar above.

Fair · Trout
Diawl Bach · 12-14
Fairlive now
Silverhorn evening rise expected on Llyn Idwal
Good wave on — drift country. A useful wave. Work the productive shore.
55% confidence
What moved it
  • WindN 8 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 8 km/h
N
N
from the north
WaveRipple
Water temp
Air temp12°C
CloudClear
Pressure1023 hPa
Rain · recent0.0 mm

Some readings unavailable — check directly before fishing.

How to fish it · for Trout
When
Late April–June; evening rises through summer
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 4 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
Ramsar-designated cirque lake in Cwm Idwal NNR — wild brown trout to 1 lb (occasionally 1.
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
Gallery · 2
  1. Llyn Idwal, a glacial lake in Cwm Idwal, Snowdonia, with still water reflecting the surrounding mountains.
    Llyn Idwal in Cwm Idwal, Snowdonia, with mist lifting off the water below the Glyderau.
  2. Terrain map of the venue
    Terrain map
About this water

Idwal is a Ramsar-designated cirque lake in Cwm Idwal NNR — eleven hectares of clear water at three hundred and seventy-three metres, beneath Y Garn and Glyder Fawr, with the Devil's Kitchen scar above. Wild brown trout to a pound, occasionally to a pound and a half. A kilometre's paved walk from Ogwen Cottage — the most accessible of the OVAA waters, and the most-walked-past. Bank fishing only; no swimming.

  • Lake
  • Ordovician volcanics
Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Murrough is in its seasonal window, boosting the chance of targeted feeding.
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