A limestone river rising from Lough Ennell and running through Offaly to the Shannon, with wild brown trout, a croneen (migratory trout) presence and small summer salmon runs. Classic midland water, best before the summer weed.
- Limestone
Rules at a glance
- Day tickets
- Walk-up OK
Water temperature for brown trout
Warm — slow21°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 21.1°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 9 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
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
Water here around 21°C. Nothing cooler within range — carry a thermometer.
About this water
The full read · show the working · for brown trout · confidence 80%
How the 21 is built — score × weight = contribution
Temperature13 × 28%3.6
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity61 × 12%7.3
Limiting factor: Water temperature (21.1°C) is outside Brown Trout's preferred range (10–16°C)= 58
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
Seasons & zones
- Trout1 March → 30 September
Related guides
Booking & contacts
River Brosna
Terrain map
A limestone river rising from Lough Ennell and running through Offaly to the Shannon, with wild brown trout, a croneen (migratory trout) presence and small summer salmon runs.
Water temperature for brown trout
Warm — slow21°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 21.1°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 9 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
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
Water here around 21°C. Nothing cooler within range — carry a thermometer.
About this water
A limestone river rising from Lough Ennell and running through Offaly to the Shannon, with wild brown trout, a croneen (migratory trout) presence and small summer salmon runs. Classic midland water, best before the summer weed.
- Limestone
The full read · show the working · for brown trout · confidence 80%
How the 21 is built — score × weight = contribution
Temperature13 × 28%3.6
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity61 × 12%7.3
Limiting factor: Water temperature (21.1°C) is outside Brown Trout's preferred range (10–16°C)= 58
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
Seasons & zones
- Trout1 March → 30 September
Related guides
Booking & contacts