Upland Natural Lake · Sandstone · Powys / Brecon Beacons, GB-WLS

Llyn Cwm Llwch

Llyn Cwm Llwch

Glacial corrie llyn in the Brecon Beacons below Corn Du.

Fair · Trout
Cat's Whisker · 8-12
Fairlive now
Good drifting conditions on Llyn Cwm Llwch
Useful ripple, fishable wave. Worth a session if the wind holds.
59% confidence
What moved it
  • WindS 23 km/hModerate breeze
Today's fly
Cat's Whisker
Cat's Whisker8-12
Retrieve, sub-surface
Conditions on the water
Estimate
Wind
Moderate breeze
S 23 km/h
N
S
from the south
Wave40 cm chop
Water temp14.9°C
Air temp14°C
CloudOvercast
Pressure1004 hPa
Rain · recent0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

How to fish it · for Trout
When
June to August
Where
Work a bushy searching pattern on the bob and drop a contrasting nymph on the point.
The plan
Plan A

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

Keep an eye on changing conditions — wind shifts and cloud breaks can trigger short feeding spells.

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 as a supporter.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 5 as a supporter.

Start free trial

14-day free trial. Cancel anytime.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Heather FlyHatch
2
2
Daddy Long LegsHatch
2
3
2
Claret DunHatch
2
3
2
Murrough (Great Red Sedge)Hatch
2
3
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Trout fly box

More straightforward stocked-water behaviour than the upland competition reservoirs, with stronger early-season lure and booby bias but still good natural-fly periods.

What's coming
Plan ahead
5-day outlook
Condition match
51%
Cloud70%
Wind30%
Temp60%

A reasonable day here, though wind isn't quite in the sweet spot.

Other water nearby · 5
Gallery · 2
  1. Llyn Cwm Llwch
  2. Terrain map of the venue
    Terrain map
About this water

Glacial corrie llyn in the Brecon Beacons below Corn Du. Wild brown trout in dramatic mountain scenery. Access by 2-mile walk from Storey Arms. Classic Beacons hill llyn — small, wild fish in clear water. Traditional wet flies and dabblers.

  • Lake
  • Sandstone
Why this score
  • Wind conditions (windy) are not ideal for this water.
  • Daddy Longlegs are in their seasonal window, boosting the chance of targeted feeding.
Directions
Seasons & zones
  • Trout 3 March → 30 September
Related guides
Casting instructors near here
Booking & contacts