Stillwater · Ordovician Volcanics · Wales / Snowdonia (Conwy catchment)

Llyn Goddionduon

Calm forest-edged lake with a small wooden boathouse tucked among trees on the far shore, near Betws-y-Coed in Snowdonia.

Goddionduon is the sort of name that trips up anyone not fluent in Welsh place-names, and the sort of lake that rewards the trouble of learning to say it properly.

Fair · Trout
Diawl Bach · 12-14
Fairlive now
Good drifting conditions on Llyn Goddionduon
Good wave on — drift country. A useful wave. Work the productive shore.
58% confidence

Llyn Goddionduon is often best in spring through autumn.

What moved it
  • WindSW 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
SW 9 km/h
N
SW
from the south-west
WaveRipple
Water temp
Air temp20°C
CloudBroken
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. Keep a sedge-style dry or emerger on a short leader for the evening rise.
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. Keep a sedge-style dry or emerger on a short leader for the evening rise.

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

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 · 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
Gammarus Scud (Olive)
Gammarus Scud (Olive)
10-14 · Gammarus Scud
Washing-line, sub-surface
Bays & launches · 1
Day ticket via Betws-y-Coed Anglers ClubAccess varies
Small, quiet hill lake above Betws-y-Coed alongside the club's other waters; wild brown trout, walk-in only.
What's coming
Plan ahead
5-day outlook
Condition match
88%
Cloud100%
Wind100%
Temp60%

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

Other water nearby · 5
Gallery · 2
  1. Calm forest-edged lake with a small wooden boathouse tucked among trees on the far shore, near Betws-y-Coed in Snowdonia.
    Looking towards the boathouse at Llyn Goddionduon
  2. Terrain map of the venue
    Terrain map
About this water

Goddionduon is the sort of name that trips up anyone not fluent in Welsh place-names, and the sort of lake that rewards the trouble of learning to say it properly. It sits in the hills above Betws-y-Coed alongside the club's other waters, small and unbothered, the kind of place you fish as much for the walk as for the water itself. The wild browns are exactly what you'd expect from a lake this size and this high up — quick, plentiful on a good evening, sulking under a hard blue sky. No boat, no frills, just heather and a rod. Go when the wind's soft and the light's fading, and don't feel obliged to tell anyone where you've been.

  • Lake
  • Ordovician volcanics
Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Cloud cover (cloud) suits the fishery well.
  • Sedge is in its seasonal window, boosting the chance of targeted feeding.
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