Stillwater · Ordovician Volcanics · Wales / Snowdonia (Glyderau)

Llyn Idwal

Llyn Idwal, a glacial lake in Cwm Idwal, Snowdonia, with still water reflecting the surrounding mountains.
Marginal · Trout
Marabou Damsel · 8-12
A patient day, if you fancy it
Good wave on — drift country. Slow going — pick your moments and do not force it.
44% confidence
limited data

Llyn Idwal is often best in spring through autumn.

What moved it
  • WindN 12 km/hLight breeze
Today's fly
MD
Marabou Damsel8-12
Retrieve, sub-surface
Conditions on the water
Live gauge
Wind
Light breeze
N 12 km/h
N
N
from the north
Wave20 cm ripple
Water temp—
Air temp17°C
CloudOvercast
Pressure1019 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

Watch for Sedge towards evening — this could be the best window of the day.

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 3 guilds with Pro.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 5 with Pro.

Start free trial

14-day free trial. Cancel anytime.

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.
Visit official site ↗
What's coming
Plan ahead
5-day outlook
Condition match
85%
Cloud50%
Wind100%
Temp100%

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

Other water nearby · 5
Llyn Bochlwyd
1.0 km
Brown trout
Llyn Ogwen
2.0 km
Brown trout · Rainbow trout
Ffynnon Lloer
3.0 km
Brown trout
Llynnau Mymbyr
5.0 km
Brown trout
Llyn Padarn
7.0 km
Brown trout · Arctic char
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
Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Temperature (cool) is in the sweet spot for summer fishing.
  • 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
Casting instructors near here
Booking & contacts