Spate · Old Red Sandstone · Mid Wales / Powys (Black Mountains, Wye tributary via Talgarth)

Llynfi

The Afon Llynfi river near Pontithel in Powys, Wales, flanked by trees and fields.

A Black Mountains spate stream — the Llynfi and its own tributary the Llynfi Dulas — running off Old Red Sandstone ground down through Talgarth to join the Wye near Glasbury.

Prime · Chub
Daddy Longlegs · Hook 10–12 with knotted pheasant tail legs
Primelive now
About as good as it gets
River dropping into shape after a lift. The kind of afternoon you remember — a weighted nymph through the clearing seams, the dry as it settles.
65% confidence
What moved it
  • LevelProxyvia Wye
  • Water temp22.1°C
  • ClarityVery colouredColouring up
Today's fly
DL
Daddy LonglegsHook 10–12 with knotted pheasant tail legs
in season · matches water height
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Wye
Water temp22.1°C
ClarityVery coloured
Weather28°C
WindW 15 km/h
Pressure1019 hPa
Rain · recent0.0 mm
Rain · ahead1.3 mm

No gauge on this water — conditions are inferred from Wye. The trend transfers, the absolute level does not.

Water temperature for Chub
Warm — slow
22°C est.ideal 14–22°C
0°14°28°
How to fish it · for Chub
Where
A Black Mountains spate stream — the Llynfi and its own tributary the Llynfi Dulas — running off Old Red Sandstone ground down through Talgarth to join the…
Why this works
Chub: comfort conditions look perfect. Clarity very coloured — accounted for via spook-risk.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 5 active hatches hour by hour with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 2 with Pro.

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Evidence
Survey-backed · regionalHigh confidence

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

Updated 9 hours ago

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Daddy Long LegsHatch
2
3
2
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2

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

Ranked for today
Chub fly box

Traditional wild-trout llyn fishing. Wet flies and dabblers stay central, with buzzer, caddis, terrestrials and occasional small fry patterns becoming important as the season warms.

SB
Small Black Streamer
Hook 8–10 weighted · Fly
in season · matches water height
Beats · 4 · 1 reaches
Llynfi beats — Fishing Passport · 4 beatsDay rods
Llynfi Dulas — Lower, Llynfi Dulas — Middle, Talgarth, Pontithel
The 4 beats
Llynfi Dulas — LowerDay tickets
Wye & Usk Foundation (Fishing Passport — Wild Streams)
1.25 miles from the Llynfi confluence up to Tregunter Farm — short, overgrown single (right) bank near the start, opening to double bank past a caravan park. One of the highest trout densities of any Wye tributary. Spectacular mayfly hatch. 2 fish/rod limit, sub-9in returned.
Wild Stream pre-booking or Season Permit.
Llynfi Dulas — MiddleDay tickets
Wye & Usk Foundation (Fishing Passport — Wild Streams)
Over 1 mile of single-bank Llynfi Dulas from Tregunter Farm up to Pont-y-Bat bridge — part of over 4 miles of Wild Streams access on the Llynfi and Llynfi Dulas combined, plus a further mile of Llynfi via the Booking Office.
Wild Stream pre-booking or Season Permit. Chest waders really required.
TalgarthDay tickets
Wye & Usk Foundation (Fishing Passport — Wild Streams)
~1 mile mixed double/single-bank River Llynfi near Talgarth, extended in 2019 below Bronllys Castle bridge. The widest species list of any Wild Streams beat — wild brown trout plus grayling, chub and shoals of perch.
Wild Stream pre-booking or Season Permit. Full C&R, mandatory online catch return.
PontithelDay tickets
Wye & Usk Foundation (Fishing Passport — Wild Streams)
~0.75 mile double-bank River Llynfi, 2 miles upstream of the Llynfi/Wye confluence, near Pontithel. Trout and grayling, with some large fish present; a dedicated Winter Grayling ticket is also sold.
Wild Stream pre-booking or Season Permit. Felt/studded soles necessary despite straightforward wading.
What's coming
Plan ahead
5-day outlook
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Gallery · 2
  1. The Afon Llynfi river near Pontithel in Powys, Wales, flanked by trees and fields.
    The Afon Llynfi near Pontithel, Powys, flowing through the Wye valley countryside.
  2. Terrain map of the venue
    Terrain map
About this water

A Black Mountains spate stream — the Llynfi and its own tributary the Llynfi Dulas — running off Old Red Sandstone ground down through Talgarth to join the Wye near Glasbury. Fishing Passport's Wild Streams scheme covers over 4 miles here, and it's reckoned among the best wild brown trout density of any Wye tributary, with a genuine mayfly hatch, some grayling, and the widest species list of any Wild Streams beat lower down (chub and perch alongside the trout).

  • Old red sandstone
The full read · show the working · for Chub · confidence 65%
Perfect · warmwater comfort — temperature and clarity led
Water temperatureWater temp 22.1°C — prime band for chub.
FlowStable flow — predictable holding lies.
SeasonPrime month for this species.
Water clarityClarity very coloured — accounted for via spook-risk.
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Wyeproxy
Related guides
Grayling Playbookgrayling tacticsYorkshire & SpidersNorth Country methodsEuro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts