Stillwater · Limestone · North Wales / Powys, GB-WLS

Lake Vyrnwy

Broad view of Lake Vyrnwy reservoir with calm water, wooded hillsides, and the shoreline stretching into the distance.

Lake Vyrnwy is the reservoir that made fly fishing accessible to the ordinary angler.

Fair · Rainbow
Olive Damsel · 10-12
Fairlive now
Reasonable summer fishing likely at Lake Vyrnwy
Good wave on — drift country. A useful wave. Work the productive shore.
60% confidence

Lake Vyrnwy is often best in spring through autumn.

What moved it
  • WindN 13 km/hGentle breeze
Today's fly
Olive Damsel
Olive Damsel10-12
Retrieve, sub-surface
Conditions on the water
Live gauge
Wind
Gentle breeze
N 13 km/h
N
N
from the north
Wave20 cm ripple
Water temp
Air temp17°C
CloudBroken
Pressure1020 hPa
Rain · recent0.0 mm

Some readings unavailable — check directly before fishing.

How to fish it · for Rainbow
When
Current conditions suit Lake Vyrnwy well for summer tactics. The ripple should help fish move and feed more confidently.
Where
Start with Olive Damsel (10-12) — on the point. 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.
The plan
Plan A

Start with Olive Damsel (10-12) — on the point. 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.

Plan B

Fish early and late, try deeper during the heat of the day with a fast-sinking line.

Watch for

Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.

Either bank or boat

Good ripple suits both bank and boat. Bank: work inflows, dam walls, and points. Boat: broadside drift covering wind lanes.

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 5 with Pro.

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Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
Daphnia SwarmHatch
2
3
3
3
2
Daddy Long LegsHatch
2
3
2
Lake OliveHatch
2
3
3
3
3
3
2
Silverhorns & LonghornsHatch
1
2
2
2
1

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

Ranked for today
Rainbow fly box

Boat-friendly, competition-influenced, often wind-driven, with strong top-of-water periods but also classic deep searching and washing-line phases.

What's coming
Plan ahead
5-day outlook
Condition match
86%
Cloud100%
Wind65%
Temp100%

Conditions are ideal for Lake Vyrnwy — wind, cloud and temperature all line up.

Other water nearby · 5
Gallery · 6
  1. Broad view of Lake Vyrnwy reservoir with calm water, wooded hillsides, and the shoreline stretching into the distance.
    Lake Vyrnwy reservoir
  2. The Victorian Gothic straining tower and approach bridge standing in Lake Vyrnwy, reservoir water surrounding it.
    Lake Vyrnwy straining tower
  3. The stone dam wall of Lake Vyrnwy with the reservoir impounded behind it and wooded hillsides on the far bank.
    Lake Vyrnwy dam and reservoir
  4. Elevated panoramic view over Lake Vyrnwy showing the dam, the straining tower, and the full length of the reservoir.
    Lake Vyrnwy from Craig garth-bwlch
  5. Drone aerial photograph over Lake Vyrnwy reservoir in autumn, the open water ringed by forested hillsides.
    Lake Vyrnwy from the air
  6. Terrain map of the venue
    Terrain map
About this water

Lake Vyrnwy is the reservoir that made fly fishing accessible to the ordinary angler. Built in 1889 and now managed by Scottish Water, Vyrnwy holds a special place in British fly-fishing history — it was here that the dry-fly revolution began on still water, where Sutherland and his peers proved that a trout rising on a reservoir could be taken with the same delicate tactics used on chalk streams. The water is fished from bank and boat, and the limestone geology produces reliable food patterns. Buzzers hatch from April, damsels from June, and sedges cloud the evening air through late summer. The valley setting and native woodland give it a wild, unhurried feel despite the managed access. This is a pilgrimage water — worth scheduling your life around.

  • Reservoir
  • Limestone
Water quality (WFD)
  • EcologyModerate
  • ChemicalUnknown
What this classification means

NRW WFD Cycle 3 (lake) — Llyn Efyrnwy / Lake Vyrnwy: 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) · GB30935568

Why this score
  • Cloud cover (cloud) suits the fishery well.
  • Temperature (cool) is in the sweet spot for summer fishing.
  • Daddy Longlegs are in their seasonal window, boosting the chance of targeted feeding.
Directions
Seasons & zones
  • Trout 15 March5 October
Related guides
Casting instructors near here
Booking & contacts
Clubs & associations