Limestone · Shannon / Offaly

Little Brosna River

Little Brosna River terrain map
Terrain map

A rich limestone river and callows system on the Offaly–Tipperary border draining to the Shannon near Lough Derg.

Marginal · Brown Trout
Pheasant Tail Nymph · 14-18
Marginallive now
Slow going — pick your moments
Low and clear — careful approach country. Cover and shadow are doing the work today.
80% confidence
What moved it
  • LevelDry recentlyNo gauge reading
  • Water temp20.2°C
  • ClarityClear
Today’s fly
Pheasant Tail Nymph
Pheasant Tail Nymph14-18
Upstream
Conditions on the water
Estimate
Level
Dry recently
No gauge reading
Water temp20.2°C
ClarityClear
Weather30°C
WindSE 24 km/h
Pressure1012 hPa
Rain · recent0.0 mm
Rain · ahead8.5 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for brown trout
Warm — slow
20°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
⚠️ Water at 20.2°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots. Otherwise poor — water clarity is in the right range.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 10 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
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
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
Water here around 20°C. Nothing cooler within range — carry a thermometer.
About this water

A rich limestone river and callows system on the Offaly–Tipperary border draining to the Shannon near Lough Derg. Wild brown trout, plus a croneen (Lough Derg migratory trout) run especially associated with the Little Brosna/Camcor system from July onwards.

  • Limestone
The full read · show the working · for brown trout · confidence 80%
How the 26 is built — score × weight = contribution
Temperature23 × 28%6.4
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity58 × 12%7.0
Limiting factor: Water temperature (20.2°C) is outside Brown Trout's preferred range (10–16°C)= 62
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
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