Lowland · Mixed · East / Meath

Mongagh & Yellow Rivers

Mongagh & Yellow Rivers terrain map
Terrain map

Two small Boyne tributaries near Castlejordan — the Mongagh coming down from near Tyrrellspass, the Yellow from north of Daingean.

Marginal · Brown Trout
Pheasant Tail Nymph · 14-18
Marginallive now
Slow going — pick your moments
River dropping into shape after a lift. A short window. Take your time.
55% confidence
What moved it
  • LevelProxyvia Boyne
  • Water temp12.2°C
  • ClarityVery colouredColouring up
Today’s fly
Pheasant Tail Nymph
Pheasant Tail Nymph14-18
Upstream
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Boyne
Water temp12.2°C
ClarityVery coloured
Weather29°C
WindE 21 km/h
Pressure1014 hPa
Rain · recent0.0 mm
Rain · ahead3.6 mm

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

Water temperature for brown trout
Ideal
12.2°Cideal 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
Poor — water temperature is working for you, but water clarity is the limiting factor today.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 12 active hatches hour by hour with Pro.

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Through the year
0–3 scale · June highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Daddy Long LegsHatch
2
3
2
Terrestrial BeetlesHatch
2
3
3
2
Blue Winged OliveHatch
1
2
2
2
2
1
Black MidgeHatch
1
2
2
2
2
2
2
2
2
2
2
1

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

Ranked for today
Brown Trout fly box
What's coming
Plan ahead
5-day outlook
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30
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30
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Lough Ennell
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Brown trout · Pike
About this water

Two small Boyne tributaries near Castlejordan — the Mongagh coming down from near Tyrrellspass, the Yellow from north of Daingean. Both hold good stocks of small wild brown trout, with better fish to two pounds in the lower reaches below Clongall Bridge. Edenderry & Castlejordan Angling Association controls the fishing and runs it catch-and-release, with sanctuary areas in operation — so it pays to check which stretches are open before you set off.

  • Mixed
The full read · show the working · for brown trout · confidence 55%
How the 30 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity15 × 18%2.7
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity48 × 12%5.8
Limiting factor: Water is very coloured — too coloured for Brown Trout= 67
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowproxy via Boyneproxy
What would change the calculation
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout1 March → 30 September
Related guides
ConnemaraIrish fishingEuro Nymphingsubsurface methods
Booking & contacts