Start with Diawl Bach (12-14) — on the bob / top dropper — slow figure-of-eight retrieve. Evening can produce explosive surface takes — try a foam beetle or booby on a long leader. 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.
Buzzers may strengthen through the middle of the day as conditions warm.
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 3 with Pro.
Start free trial14-day free trial. Cancel anytime.
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Boat-friendly, competition-influenced, often wind-driven, with strong top-of-water periods but also classic deep searching and washing-line phases.
Conditions are ideal for Llyn Brenig — wind, cloud and temperature all line up.
919-acre upland reservoir on the Hiraethog moors above Cerrigydrudion. One of Wales's premier stillwater trout fisheries — boat and bank. Stocked with brown and rainbow trout, with wild browns breeding in feeder streams. Competition venue. Excellent buzzer, Diawl Bach and damsel fishing. Visitor centre and boats from sailing club end.
NRW WFD Cycle 3 (lake) — Llyn Brenig: Moderate ecological status. Re-tagged 2026-06-18 from a feeder-river reach to the reservoir's own lake waterbody. Source: NRW DataMapWales WFD Cycle 3 classification layer.
NRW (Wales) · GB31133923
919-acre upland reservoir on the Hiraethog moors above Cerrigydrudion.
Start with Diawl Bach (12-14) — on the bob / top dropper — slow figure-of-eight retrieve. Evening can produce explosive surface takes — try a foam beetle or booby on a long leader. 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.
Buzzers may strengthen through the middle of the day as conditions warm.
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 3 with Pro.
Start free trial14-day free trial. Cancel anytime.
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Boat-friendly, competition-influenced, often wind-driven, with strong top-of-water periods but also classic deep searching and washing-line phases.
Conditions are ideal for Llyn Brenig — wind, cloud and temperature all line up.
919-acre upland reservoir on the Hiraethog moors above Cerrigydrudion. One of Wales's premier stillwater trout fisheries — boat and bank. Stocked with brown and rainbow trout, with wild browns breeding in feeder streams. Competition venue. Excellent buzzer, Diawl Bach and damsel fishing. Visitor centre and boats from sailing club end.
NRW WFD Cycle 3 (lake) — Llyn Brenig: Moderate ecological status. Re-tagged 2026-06-18 from a feeder-river reach to the reservoir's own lake waterbody. Source: NRW DataMapWales WFD Cycle 3 classification layer.
NRW (Wales) · GB31133923
