Spate · Mixed · South Wales / Cardiff / Caerphilly

River Rhymney

No photos yet for this water.

Down the Rhymney Valley from the head of the South Wales coalfield through Bedwas and the eastern Cardiff suburbs to the Severn estuary.

Species

About as good as it gets

Low and clear — careful approach country. Take your time — read the water before you cast.

75% confidence in this read
Water temperature for brown trout
Ideal
11°C est.ideal 1016°C
0°14°28°
Why this score · for brown trout
  • Temperature10028% weight
  • Flow8022% weight
  • Clarity9518% weight
  • Feeding Time5013% weight
  • Pressure807% weight
  • Prey Activity5112% weight
Conditions
Level
Dry recently
No gauge reading
Water temp
11.1°C
Estimated
Clarity
Clear
Air temp
19°C
Wind
NE 6 km/h
Light breeze
Pressure
1030 hPa
Rain · 48h
0.0 mm
No meaningful rain
Rain · ahead
0.0 mm
No meaningful rain · next 48h

Live readings — water temperature is an estimate where the gauge does not record it.

How to fish it · for brown trout
When
Through the open trout season. Spring olives and summer sedges through the middle valley; fly life improving with catchment recovery.
Where
Middle Rhymney through the valley above the Cardiff suburbs. Pool tails and runs through farmland.
Method
Upstream dry to risers through summer; dry-dropper through the runs. Where the river slows through farmland, longer leaders and lighter tippet earn the takes. Spider patterns on the swing when olives are off the water.
Kit
9 ft #4. Floating line, 12 ft leader to 4 to 5 lb fluoro. Wading is usually easy on the lower reaches — the upper valley is rockier.
Why this works
Excellent conditions. Temperature is favourable (100), Feeding time is weakest (50).
Through the year
0–3 scale · May highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Salmon runRun
1
2
2
2
2
1
Sea trout runRun
1
2
2
2
2
2
2
1
Trout seasonSeason
1
2
2
2
2
2
1
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2
Yellow SallyHatch
2
3
2

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

Directions
About this water

Down the Rhymney Valley from the head of the South Wales coalfield through Bedwas and the eastern Cardiff suburbs to the Severn estuary. Another industrial-recovery story — wild brown trout through the middle valley, sewin on the autumn lifts, the salmon side a genuine rumour rather than a fishery. Like its neighbours the Taff and Ely, the Rhymney is more interesting than its postcode would suggest, and the recovery work continues.

  • Mixed
Seasons & zones
  • Salmon1 May → 17 October
  • Sea trout3 March → 17 October
  • Trout3 March → 30 September

Sea trout: Variable seasonal (2026) — Recovering industrial valley river; sewin work up on autumn lifts in modest numbers. All-Wales At Risk picture applies. The Rhymney's value as a fishery is in its recovery, not in destination angling.

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