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.
Rules at a glance
- Day tickets
- Fly only
Good late spring conditions for Llyn Clywedog
Good wave on — drift country. A useful wave. Work the productive shore.
Current conditions suit Llyn Clywedog well for late spring tactics. The ripple should help fish move and feed more confidently.
63% confidence in this read
Live now
Conditions on the water
Trends shown where the gauge supports them
Wind
W 14 km/h
Gentle breeze
Wave
20 cm ripple
Water temp
—
No reading
Air temp
7°C
Cloud
Broken
Pressure
—
Rain · 24h
0.0 mm
No rain
Some readings unavailable — check directly before fishing.
How to fish · for rainbow trout
The brief
When · where · method · kit
How to fish it · for rainbow trout
When
Late spring start — May through September is the practical window. Buzzers May into June; sedges through summer; lures for the back-end. Mountain weather changes fast.
Where
Open water boat marks; the dam and the deeper bays. Clywedog's depth means fish go down quickly in summer warm.
Method
Floater with buzzers under indicator in late spring; midge-tip in summer; sweeping line with lures when fish hold deep.
Kit
10 ft #7 boat rod; floating, intermediate and fast-intermediate lines; 6 to 8 lb fluoro. Drogue and a long-handled net.
Today's tactical plan
The plan
Plan A · Plan B · what to watch · bank or boat
The plan
Plan A
Start with Blob (8-10) on a fast strip on floating line or static on sinking. Rainbows respond to more active retrieves — try short strips between pauses. If that does not produce, switch depth or speed before changing the pattern entirely. When no hatch is visible, a buzzer team — black stripped quill on the point, attractor or pearl-rib on the top dropper — is the default starting point on any UK stillwater.
Plan B
If fish refuse on top, drop to a buzzer under an indicator at different depths.
Watch for
Keep an eye on changing conditions — wind shifts and cloud breaks can trigger short feeding spells.
Either bank or boat
Good ripple suits both bank and boat. Bank: work inflows, dam walls, and points. Boat: broadside drift covering wind lanes.
Hatches & runs
What's on, when
Twelve months at a glance
Through the year
0–3 scale · May highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2
Reservoir BuzzerHatch
2
3
3
3
3
3
2
Daphnia SwarmHatch
2
3
3
3
2
Lake OliveHatch
2
3
3
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Today's fly · curated pack
Top pattern + the box
4 patterns from this venue's curated pack
Evidence
Why today scores what it does
The factors driving today's verdict
Why this score
- Wind conditions (breezy) closely match what this water fishes best in.
- Cloud cover (cloud) suits the fishery well.
Detail · next 12h
Precipitation
The reading most likely to move tomorrow's verdict
About this water · Lough note · 4 min read
Llyn Clywedog · profile
Who this water suits
Strengths · watch-outs · best for
About this water
Llyn Clywedog, on the water
Field guide · contributor-editedLlyn Clywedog · about
What this water is
Background · character · contributors
About this water
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.
- Reservoir
- Slate
Llyn Clywedog · directions
How to get to the water
Directions
Llyn Clywedog · zones
Where the rules change
Seasons · zones · per-species rules
Seasons & zones
- TroutLate March → Mid October
Llyn Clywedog
Terrain map
615-acre reservoir in the upper Severn headwaters near Llanidloes.
Species
Good late spring conditions for Llyn Clywedog
Good wave on — drift country. A useful wave. Work the productive shore.
Current conditions suit Llyn Clywedog well for late spring tactics. The ripple should help fish move and feed more confidently.
63% confidence in this read
Conditions
Wind
W 14 km/h
Gentle breeze
Wave
20 cm ripple
Water temp
—
No reading
Air temp
7°C
Cloud
Broken
Pressure
—
Rain · 24h
0.0 mm
No rain
Some readings unavailable — check directly before fishing.
Condition match
88%
Cloud100%
Wind100%
Temp60%
Conditions are ideal for Llyn Clywedog — wind, cloud and temperature all line up.
How to fish it · for rainbow trout
When
Late spring start — May through September is the practical window. Buzzers May into June; sedges through summer; lures for the back-end. Mountain weather changes fast.
Where
Open water boat marks; the dam and the deeper bays. Clywedog's depth means fish go down quickly in summer warm.
Method
Floater with buzzers under indicator in late spring; midge-tip in summer; sweeping line with lures when fish hold deep.
Kit
10 ft #7 boat rod; floating, intermediate and fast-intermediate lines; 6 to 8 lb fluoro. Drogue and a long-handled net.
The plan
Plan A
Start with Blob (8-10) on a fast strip on floating line or static on sinking. Rainbows respond to more active retrieves — try short strips between pauses. If that does not produce, switch depth or speed before changing the pattern entirely. When no hatch is visible, a buzzer team — black stripped quill on the point, attractor or pearl-rib on the top dropper — is the default starting point on any UK stillwater.
Plan B
If fish refuse on top, drop to a buzzer under an indicator at different depths.
Watch for
Keep an eye on changing conditions — wind shifts and cloud breaks can trigger short feeding spells.
Either bank or boat
Good ripple suits both bank and boat. Bank: work inflows, dam walls, and points. Boat: broadside drift covering wind lanes.
Why this score
- Wind conditions (breezy) closely match what this water fishes best in.
- Cloud cover (cloud) suits the fishery well.
Through the year
0–3 scale · May highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2
Reservoir BuzzerHatch
2
3
3
3
3
3
2
Daphnia SwarmHatch
2
3
3
3
2
Lake OliveHatch
2
3
3
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Directions
About this water
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.
- Reservoir
- Slate
Seasons & zones
- TroutLate March → Mid October
About this water · Lough note · 4 min read
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.
Other water nearby · 5
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