- Ecology: Good
- Chemical: Unknown
WFD classification · FRGR0073
Rules at a glance
- Day tickets
Water temperature for Brown Trout
Warm — slow19°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season. Spring olives April through May; sedges through summer; small dark flies into autumn close.
Where
Pool tails and the seams behind boulders through the central Brittany stretches. The Aulne is bigger water than most Breton rivers.
Method
Upstream dry to risers; dry-dropper through the riffles. Breton spate freestone — fish 12 to 24 hours after rain on the drop. Long leader, fine tippet.
Kit
9 ft #4 — Breton spate freestone. Floating line, 12 ft leader to 4 lb fluoro. Studded boots.
Why this works
Water at 18.6°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 4 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 2 with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalModerate 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
Trout seasonSeason
1
2
2
2
2
2
1
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2
Yellow SallyHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Brown Trout fly box
Permits & access
Permit required — see local rules.
- AAPPMA permits
- Regional arrêté for season.
What's coming
Plan ahead
5-day outlook
Water here around 19°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Aulne — image via Wikipedia (Aulne) Terrain map
Water quality (WFD)
The full read · show the working · for Brown Trout · confidence 80%
How the 36 is built — score × weight = contribution
Temperature46 × 28%12.9
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity60 × 12%7.2
Conditions total= 66
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
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
- Trout 2nd Saturday of March → 3rd Sunday of September
Salmon: Banned (2026) — Brittany 2026 order bans Atlantic salmon and sea trout on all Breton rivers.
Sea trout: Banned (2026) — Brittany 2026 order bans Atlantic salmon and sea trout on all Breton rivers.
Related guides
Booking & contacts
Aulne
Water temperature for Brown Trout
Warm — slow19°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season. Spring olives April through May; sedges through summer; small dark flies into autumn close.
Where
Pool tails and the seams behind boulders through the central Brittany stretches. The Aulne is bigger water than most Breton rivers.
Method
Upstream dry to risers; dry-dropper through the riffles. Breton spate freestone — fish 12 to 24 hours after rain on the drop. Long leader, fine tippet.
Kit
9 ft #4 — Breton spate freestone. Floating line, 12 ft leader to 4 lb fluoro. Studded boots.
Why this works
Water at 18.6°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 4 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 2 with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalModerate 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
Trout seasonSeason
1
2
2
2
2
2
1
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2
Yellow SallyHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Brown Trout fly box
Permits & access
Permit required — see local rules.
- AAPPMA permits
- Regional arrêté for season.
What's coming
Plan ahead
5-day outlook
Water here around 19°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Aulne — image via Wikipedia (Aulne) Terrain map
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · FRGR0073
The full read · show the working · for Brown Trout · confidence 80%
How the 36 is built — score × weight = contribution
Temperature46 × 28%12.9
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity60 × 12%7.2
Conditions total= 66
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
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
- Trout 2nd Saturday of March → 3rd Sunday of September
Salmon: Banned (2026) — Brittany 2026 order bans Atlantic salmon and sea trout on all Breton rivers.
Sea trout: Banned (2026) — Brittany 2026 order bans Atlantic salmon and sea trout on all Breton rivers.
Related guides
Booking & contacts