Limestone · West / Mayo

Lough Conn / Lough Cullin

Wide panoramic view north across Lough Conn from Pontoon Bridge, County Mayo.

Twin loughs connected by a short channel near Pontoon — different characters despite their proximity.

Marginal · Atlantic Salmon
Cascade · 10-14
Marginallive now
Marginal — persistence required
River steady at a fishable height. A short window at best — fish the sure lies and move on.
85% confidence
What moved it
  • Level0.97 mLast reading 11h ago
  • Water temp18.0°C
  • ClarityClear
Today's fly
Cascade
Cascade10-14
Regional salmon default — river-specific evidence is thin.
Conditions on the water
Live gauge
Level
Steady
0.97 m
Last reading 11h ago
Water temp18.0°C
ClarityClear
Weather21°C
WindS 17 km/h
Pressure1019 hPa
Rain · recent0.0 mm
Rain · ahead0.8 mm

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

Water temperature for Atlantic Salmon
Warm — slow
18°C est.ideal 10–14°C
0°14°28°
How to fish it · for Atlantic Salmon
When
Salmon run through from the Moy system in May and June. Conn is not a destination salmon water — these are fish moving upstream. Fish dropping water after a lift.
Where
The Pontoon channel and the lower lough where salmon enter from the Moy. Don't fish the open lough for salmon — they're moving, not holding.
Method
Drift fly with team wets if you're trout fishing and a salmon comes through; otherwise this is not where to spend the week. Murrough on the bob is a known salmon take in mayfly season.
Kit
10 ft #7, intermediate plus floater, 12 lb fluoro. The trout-water rod plus heavier tippet — you're not gearing up for salmon-only here.
Why this works
Water at 18°C — above the atlantic salmon caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Likely species
Mayflies
  • Anglers curse mayfliesMost likelyLower confidence
    #20–22 · Spinner
    Go tiny: 20-22 spent spinner, single fly, long tippet.
  • Blue-winged oliveAlso possible
    #16–18 · Dun
    Duns are up; a sherry spinner fall may follow.
Caddisflies
  • Satin sedgeMost likelyLower confidence
    #12–14 · Egg-laying
    Skitter it at dusk — this one's fished, not dead-drifted.
  • Green PeterAlso possible
    #8–10–12 · Adult
    Pupa in the wave; wake a dry sedge at last light.
  • Large sedgesAlso possible
    #8–10 · Adult
    Big waked sedge in the last light and after dark.
Hatch timeline · todayPeak at 6am

Hatch predictions

Today's headline hatch shown — see all 11 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 4 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

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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
2
2
1
Trout seasonSeason
1
2
2
2
2
2
2
1
Green PeterHatch
2
3
2
Murrough (Great Red Sedge)Hatch
2
3
2
Daddy Long LegsHatch
2
3
2
Mayfly (Green Drake)Hatch
2
2

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

Ranked for today
Atlantic Salmon fly box
Permits & access
Free state water
State rod licence required for trout / salmon as applicable.
  • No permit needed — state rod licence only
  • Boats from Crossmolina, Pontoon, Foxford
  • Salmon licence additional.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 18°C — probably warm enough to stress Atlantic Salmon . These are likely cooler.
Moy
16 km
14.7°C
Brown trout · Salmon · Sea trout
Gallery · 6
  1. Wide panoramic view north across Lough Conn from Pontoon Bridge, County Mayo.
    Lough Conn from Pontoon Bridge
  2. Open water of Lough Conn viewed from the R310 Pontoon bridge.
    Lough Conn from the Pontoon Bridge
  3. Lough Conn, County Mayo, an open lough landscape.
    Lough Conn
  4. The Pontoon crossing between Lough Conn and Lough Cullin, open water on both sides.
    Pontoon, Lough Conn / Lough Cullin
  5. Lough Cullin viewed from the R310, the sister lough to Lough Conn at Pontoon.
    Lough Cullin from the R310
  6. Terrain map of the venue
    Terrain map
About this water

Twin loughs connected by a short channel near Pontoon — different characters despite their proximity. Lough Conn is limestone-fed with superb mayfly and olive fishing, clear water and responsive trout. Cullin is darker, peaty water with a different mood entirely. Together they offer the best brown trout fishing in Mayo. Salmon run through from the Moy system. Dapping is excellent when the breeze favours it.

Hatches & food

Named among the western limestone loughs for duckfly from around 17 March for about three weeks, lake olives from late April to early May, and a mayfly period from after the first week of May into early June, with Caenis at first light and sedges late in the evening through summer - though this is regional guidance, not a measured hatch on Conn itself. Lough Cullin specifically is reported to fish well on duckfly and mayfly from late March through June, before summer weed growth curtails the sport.

  • Lough system
  • Limestone
Water quality (WFD)
  • Ecology: Good
  • Chemical: Unknown
What this classification means

WFD code normalized 2026-06-18: IE_WE_34_406b → IEWE_34_406B (EPA national format → EEA WISE euSurfaceWaterBodyCode; same water body, now joinable to WISE). Status confirmed against EEA WISE 2022 (3rd RBMP). Source: discodata.eea.europa.eu. | Prior note: EPA WFD 2019-2024 (lake layer) — Lough Conn: Good ecological status. Re-tagged 2026-06-18 from IEWE_34C050100 (a river/stream water body, not the lough) to the lough's own EPA lake water body. Source: EPA Ireland WFD 2019-2024 classification (catchments.ie / EDEN).

EPA (Ireland) · IEWE_34_406B

Directions
Apple MapsGoogle Maps
Seasons & zones
  • Salmon 1 February → 30 September
  • Trout 15 February → 30 September

Sea trout: Variable seasonal (2026) — Conn (Mayo) carries sea-trout relevance but should not be modelled as a clean "primary open" signal — returns are condition-dependent and stock context tracks the wider western Irish picture.

Related guides
Irish Loughs Playbooklough-style fishingThermal Layers & Troutreading depth and temperatureAtlantic Salmonsalmon tactics
Casting instructors near here
Booking & contacts