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.

Tomorrow · Not the day for it
Bibio
Forecast · Tomorrow
Not the day for it
Not much stacked in your favour today. Worth an hour if you are nearby, not worth the special trip.
45% projected
Today's fly
Bibio
Bibio
Reading the river for Tomorrow
Not much stacked in your favour today. Worth an hour if you are nearby, not worth the special trip.
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Wye
Water temp11.7°C
ClarityClear
Weather9°C
WindW 5 km/h
Pressure1013 hPa
Rain · recent2.5 mm
Rain · ahead0.0 mm

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

Water temperature for Brown Trout
Ideal
12°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Why this works
Excellent — water temperature is right today, though insect activity could be better.
Hatch timeline · tomorrowPeak at 12pm

12pm(now) — Heather Fly

Stage: Terrestrials on topApproach: Dry flyActivity: 67%
Also:Daddy Long Legs53%Cinnamon Sedge34%Autumn Dun33%
Peak emergence windowWeather boost10 food groups active

Peak activity at 12pm — Heather Fly (Heather Fly, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds with Pro.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey

Hatch predictions

See what else is on the menu with Pro.

Start free trial

14-day free trial. Cancel anytime.

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
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
Brown Trout 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.

BU
Bumble
10-12 · Pattern
Fish it in the film
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.
Visit official site ↗
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.
Visit official site ↗
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.
Visit official site ↗
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.
Visit official site ↗
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Brynhenllys Fishery
5.0 km
Brown trout
Grwyne Fawr Reservoir
8.0 km
Brown trout
Wye
15 km
81
Brown trout · Salmon · Grayling
Talybont Reservoir
18 km
Brown trout
Edw
21 km
Brown trout · Salmon
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 Brown Trout · confidence 90%
How the 84 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity55 × 12%6.6
Conditions total= 84
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Wyeproxy
Prey activitysurvey-backed invertebrate datasurvey
Related guides
Grayling Playbookgrayling tacticsYorkshire & SpidersNorth Country methodsEuro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts