Spate · Mixed · South Wales / Cardiff / Caerphilly, GB-WLS

River Rhymney

The River Rhymney flowing past Bedwas in South Wales, a gently curving rural river stretch bordered by trees.
Prime · Sea Trout
Black & Silver Tube · 1-2 inch
Primelive now
Prime conditions — go now
Low and clear — careful approach country. Cover the water properly, fish each lie once.
90% confidence
What moved it
  • Level0.18 mLast reading 1h ago
  • Water temp12.4°C
  • ClarityClear
Today's fly
BS
Black & Silver Tube1-2 inch
In deep pools and dark water, silhouette and contrast do the work colour cannot. A fly that reads as black against depth is enough. Fish it broadside, hold the swing, let it hang at the dangle — that is when the best fish take.
Conditions on the water
Live gauge
Level
Steady
0.18 m
Last reading 1h ago
Water temp12.4°C
ClarityClear
Weather10°C
WindN 11 km/h
Pressure1025 hPa
Rain · recent0.1 mm
Rain · ahead0.3 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Sea Trout
Ideal
12°C est.ideal 8–15°C
0°14°28°
How to fish it · for Sea Trout
When
August through September — autumn lifts only. Night work once water reaches 13°C. All-Wales At Risk plus urban-recovery context — catch-and-release as a binding ethic.
Where
Lower Rhymney pool tails above the tidal limit at Cardiff. Walk the beat in daylight.
Method
Small wets — size 10 to 12 Medicine, Peter Ross, Teal Blue and Silver — across-and-down on a floating line. On falling water carry a sink-tip for the deeper pots. Fish methodically from the tail of each pool; the take comes on the swing.
Kit
9 to 10 ft #6/7, floating line plus a light sink-tip in the bag. 8 to 10 lb fluoro. The river is small enough to wade carefully between casting positions.
Why this works
Excellent — water temperature is right today, though insect activity could be better. ⏰ Sea trout become most active after dark, but this stretch closes at 19:58 — before that window fully opens. Fish hard in the last legal hour: overcast skies and warm evenings can bring fish on early even in fading light.
Hatch timeline · todayPeak at 6am

Hatch predictions

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Sub-surface · on the nymphunder the surface

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Beyond the hatch · worth watchingambient prey

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Evidence
Survey-backed · regionalHigh confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · August 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
CapererHatch
2
3
3
2
Heather FlyHatch
2
2
Autumn DunHatch
2
3
2

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

Ranked for today
Sea Trout fly box
BS
Black & Silver TubeTop
1-2 inch · Tube
In deep pools and dark water, silhouette and contrast do the work colour cannot. A fly that reads as black against depth is enough. Fish it broadside, hold the swing, let it hang at the dangle — that is when the best fish take.
SF
Snake Fly (Black)
2-4 inch · Streamer
A mobile eel-like profile that undulates through deep pools — effective when sea trout are lying deep and not responding to conventional wets.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Ebbw
7.0 km
Brown trout · Salmon · Sea trout
Sirhowy
8.0 km
Brown trout · Salmon
River Taff
11 km
80
Brown trout · Grayling · Salmon
Rhondda
11 km
Brown trout · Grayling · Salmon
Bargoed Park
12 km
Brown trout · Rainbow trout
Gallery · 2
  1. The River Rhymney flowing past Bedwas in South Wales, a gently curving rural river stretch bordered by trees.
    The River Rhymney at Bedwas, South Wales, looking west along a quiet rural stretch.
  2. Terrain map of the venue
    Terrain map
Water quality (WFD)
  • Ecology: Good
  • Chemical: Unknown
What this classification means

NRW WFD Cycle 3 — Rhymney (conf Nant Cylla to Chapel Wood, Bedwas): Good ecological status. Corrected 2026-06-18 from a Nant-Glandulas tributary tag (was recorded Moderate). Source: NRW DataMapWales WFD Cycle 3 classification layer.

EA (England) · GB109057027280

Why this score · for Sea Trout
  • Temperature10028% weight
  • Flow8022% weight
  • Clarity8518% weight
  • Feeding Time8013% weight
  • Pressure857% weight
  • Insect activity5612% weight
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Salmon 1 May → 17 October
  • Sea trout 3 March → 17 October
  • Trout 3 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.

Related guides
Yorkshire & SpidersNorth Country methodsEuro Nymphingsubsurface methods
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