Start with Coch-y-Bonddu Beetle (10-14) — on the bob / top dropper. Early in the day, try buzzers on a slow figure-of-eight or a booby on a fast-sink line near the bottom. Rainbows respond to more active retrieves — try short strips between pauses.
Fish early and late, try deeper during the heat of the day with a fast-sinking line.
Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.
Good ripple suits both bank and boat. Bank: work inflows, dam walls, and points. Boat: broadside drift covering wind lanes.
Hatch predictions
Top prey shown — see all 5 with Pro.
Start free trial14-day free trial. Cancel anytime.
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Traditional wild-trout llyn fishing. Wet flies and dabblers stay central, with buzzer, caddis, terrestrials and occasional small fry patterns becoming important as the season warms.
A good match for Llyn Clywedog — most conditions are close to what it fishes best in.
615-acre reservoir in the upper Severn headwaters near Llanidloes. Deep upland water with excellent wild brown trout and stocked rainbows. Boat and bank fishing. Strong competition pedigree. Dramatic scenery with steep valley sides. Good buzzer and sedge hatches.
NRW WFD Cycle 3 (lake) — Llyn Clywedog: Moderate ecological status. Re-tagged 2026-06-18 from an inflow-river reach to the reservoir's own lake waterbody. Source: NRW DataMapWales WFD Cycle 3 classification layer.
NRW (Wales) · GB30937446
615-acre reservoir in the upper Severn headwaters near Llanidloes.
Start with Coch-y-Bonddu Beetle (10-14) — on the bob / top dropper. Early in the day, try buzzers on a slow figure-of-eight or a booby on a fast-sink line near the bottom. Rainbows respond to more active retrieves — try short strips between pauses.
Fish early and late, try deeper during the heat of the day with a fast-sinking line.
Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.
Good ripple suits both bank and boat. Bank: work inflows, dam walls, and points. Boat: broadside drift covering wind lanes.
Hatch predictions
Top prey shown — see all 5 with Pro.
Start free trial14-day free trial. Cancel anytime.
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Traditional wild-trout llyn fishing. Wet flies and dabblers stay central, with buzzer, caddis, terrestrials and occasional small fry patterns becoming important as the season warms.
A good match for Llyn Clywedog — most conditions are close to what it fishes best in.
615-acre reservoir in the upper Severn headwaters near Llanidloes. Deep upland water with excellent wild brown trout and stocked rainbows. Boat and bank fishing. Strong competition pedigree. Dramatic scenery with steep valley sides. Good buzzer and sedge hatches.
NRW WFD Cycle 3 (lake) — Llyn Clywedog: Moderate ecological status. Re-tagged 2026-06-18 from an inflow-river reach to the reservoir's own lake waterbody. Source: NRW DataMapWales WFD Cycle 3 classification layer.
NRW (Wales) · GB30937446
