Stoneflies
Gammarids
- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRHR169
Rules at a glance
- Day tickets
Water temperature for Grayling
Warm — slow15°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime.
Where
Faster runs in the middle and lower stretches.
Method
Euro-nymphing through the deeper pockets is the daily default; switch to dries on autumn afternoons when sedges and small olives come off. Long fine tippet for the clear water.
Kit
10 ft #3 nymphing rod for the deep pockets; 9 ft #4 for dries. 4 to 5 lb fluoro tippet, 12 ft leader.
Why this works
Water at 17.6°C — above the grayling caution line (17°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Likely species
Hatch timeline · todayPeak at 15 Uhr
12 Uhr(now) — Black Gnat
Stage: On emergersApproach: Emerger or dryActivity: 46%
Also:Small Dark Olive30%
Peak emergence window7 food groups active
Peak activity at 15 Uhr — Small Dark Olive (Small Dark Olive, 12 food groups active)
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds as a supporter.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 as a supporter.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Grayling seasonSeason
1
2
2
2
2
2
2
1
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
2
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Hook 14–18 · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- AAPPMA permits.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 18°C — probably warm enough to stress Grayling . These are likely cooler.
Gallery · 2
Terrain map
Water quality (WFD)
The full read · show the working · for Grayling · confidence 80%
How the 12 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time90 × 13%11.7
Pressure80 × 7%5.6
Insect activity69 × 12%8.3
Limiting factor: Water temperature (17.6°C) is outside Grayling's preferred range (4–14°C)= 60
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 4–14 °C ideal band — would lift the score and ease welfare.
Directions
Seasons & zones
- Trout 2. Saturday im March → 3. Sunday im September
- Grayling 3. Saturday im May → 31 December
France national rule: grayling opens 3rd Saturday of May in all waters. In 2nd category waters, grayling remains open until 31 December. Departmental regulations may impose earlier closing dates. Always check the relevant département's 2026 arrêté préfectoral.
Related guides
Booking & contacts
Saâne
Water temperature for Grayling
Warm — slow15°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime.
Where
Faster runs in the middle and lower stretches.
Method
Euro-nymphing through the deeper pockets is the daily default; switch to dries on autumn afternoons when sedges and small olives come off. Long fine tippet for the clear water.
Kit
10 ft #3 nymphing rod for the deep pockets; 9 ft #4 for dries. 4 to 5 lb fluoro tippet, 12 ft leader.
Why this works
Water at 17.6°C — above the grayling caution line (17°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Likely species
Hatch timeline · todayPeak at 15 Uhr
12 Uhr(now) — Black Gnat
Stage: On emergersApproach: Emerger or dryActivity: 46%
Also:Small Dark Olive30%
Peak emergence window7 food groups active
Peak activity at 15 Uhr — Small Dark Olive (Small Dark Olive, 12 food groups active)
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds as a supporter.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 as a supporter.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Grayling seasonSeason
1
2
2
2
2
2
2
1
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
2
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Hook 14–18 · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- AAPPMA permits.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 18°C — probably warm enough to stress Grayling . These are likely cooler.
Gallery · 2
Terrain map
Water quality (WFD)
- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRHR169
The full read · show the working · for Grayling · confidence 80%
How the 12 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time90 × 13%11.7
Pressure80 × 7%5.6
Insect activity69 × 12%8.3
Limiting factor: Water temperature (17.6°C) is outside Grayling's preferred range (4–14°C)= 60
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 4–14 °C ideal band — would lift the score and ease welfare.
Directions
Seasons & zones
- Trout 2. Saturday im March → 3. Sunday im September
- Grayling 3. Saturday im May → 31 December
France national rule: grayling opens 3rd Saturday of May in all waters. In 2nd category waters, grayling remains open until 31 December. Departmental regulations may impose earlier closing dates. Always check the relevant département's 2026 arrêté préfectoral.
Related guides
Booking & contacts