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
Marabou Damsel · 8-12
A respectable few hours, if you choose your moments
Water temperature is the limiting factor today, not the wave. Fish dawn or dusk if you go at all, and handle everything with extra care.
47% confidence
limited data

Llyn Idwal is often best in spring through autumn.

What moved it
  • WindSW 11 km/hLight breeze
Today's fly
MD
Marabou Damsel8-12
Retrieve, sub-surface
Conditions on the water
Live gauge
Wind
Light breeze
SW 11 km/h
N
SW
from the south-west
Wave20 cm ripple
Water temp
Air temp23°C
CloudClear
Pressure1021 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.

Bank

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

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 · 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 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
55%
Cloud25%
Wind100%
Temp25%

A reasonable day here, though temperature 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.
  • Daddy longlegs are in their seasonal window, boosting the chance of targeted feeding.
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