Spate · Mixed · East / Louth, IE

Ballymascanlan River

The Ballymascanlan River flowing through wooded grounds in County Louth, Ireland

The Ballymascanlan rises on Slieve Gullion and runs some fourteen miles to Dundalk Bay.

Prime · Brown Trout
Pheasant Tail Nymph · 14-18
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.
90% confidence
What moved it
  • LevelProxyvia River Glyde
  • Water temp12.5°C
  • ClaritySlightly colouredClearing
Today's fly
Pheasant Tail Nymph
Pheasant Tail Nymph14-18
Upstream
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via River Glyde
Water temp12.5°C
ClaritySlightly coloured
Weather15°C
WindS 15 km/h
Pressure1020 hPa
Rain · recent20.7 mm
Rain · ahead5.6 mm

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

Water temperature for Brown Trout
Ideal
13°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 time of day could be better.
Likely species
Stoneflies
Caddisflies
Gammarids
Hatch timeline · todayPeak at 2pm

Hatch predictions

Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 as a supporter.

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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 · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
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
Brown Trout fly box
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Castletown River
4.0 km
Brown trout · Sea trout
River Dee (Louth)
16 km
30
Brown trout
River Dee (Louth)
16 km
Brown trout
River Fane
16 km
Brown trout
River Fane
16 km
Brown trout
Gallery · 2
  1. The Ballymascanlan River flowing through wooded grounds in County Louth, Ireland
    The River Ballymascanlon in the grounds of Ballymascanlon House, County Louth
  2. Terrain map of the venue
    Terrain map
About this water

The Ballymascanlan rises on Slieve Gullion and runs some fourteen miles to Dundalk Bay. It holds a modest stock of brown trout, but its summer salmon and sea trout are the draw, and the best of that lies in the pools below Ballymascanlan Bridge. This is a spate river: fish it after a flood, when fresh fish have run up on the rising water. Work the pools at night from July to September. Dundalk Brown Trout Anglers hold the day permits.

Hatches & food

A flashy Slieve Gullion spate stream where stoneflies and terrestrials outweigh upwings; hatches are sparse and flood-driven, with night sedges the key food once sea trout run in summer.

  • Mixed
The full read · show the working · for Brown Trout · confidence 90%
How the 82 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity69 × 12%8.3
Conditions total= 82
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via River Glydeproxy
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 March → 30 September

Sea trout: Variable seasonal (2026)

Related guides
ConnemaraIrish fishingEuro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts
Permits & access