Stoneflies
Caddisflies
Damselflies & dragonflies
Gammarids
- Ecology: Good
- Chemical: Unknown
WFD classification · FRDR361A
Rules at a glance
- Day tickets
Water temperature for Grayling
Ideal9°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime.
Where
Faster runs and the heads of riffles through the middle valley.
Method
Euro-nymphing through the deeper pockets; switch to dries when sedges or olives come off in autumn afternoons.
Kit
10 ft #3 nymphing rod for the deep pockets; 9 ft #4 for dries. 4 to 5 lb fluoro tippet, 12 ft leader.
Likely species
Caddisflies
Damselflies & dragonflies
Hatch timeline · tomorrowPeak at 13 Uhr
12 Uhr(now) — Autumn Olive
Stage: On emergersApproach: Emerger or dryActivity: 57%
Also:Black Midge51%Autumn Needle Fly51%
Peak emergence window8 food groups active
Peak activity at 13 Uhr — Iron Blue (Iron Blue, 9 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
Supporters see what else is on the menu.
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
1
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
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.
- Savoie AAPPMA permits.
What's coming
Plan ahead
5-day outlook
Fishing better nearby · 5
Gallery · 2
Terrain map
Water quality (WFD)
The full read · show the working · for Grayling · confidence 75%
How the 0 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time50 × 13%6.5
Pressure80 × 7%5.6
Insect activity52 × 12%6.2
Conditions total= 79
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 2. Saturday im March → 3. Sunday im September
- Grayling 3. Saturday im May → 3. Sunday im September
France national rule: grayling opens 3rd Saturday of May in all waters. In 1st category (salmonid) rivers, grayling closes with the trout season on the 3rd Sunday of September. Departmental regulations may impose additional restrictions. Always check the relevant département's 2026 arrêté préfectoral.
Related guides
Booking & contacts
Arc
Water temperature for Grayling
Ideal9°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime.
Where
Faster runs and the heads of riffles through the middle valley.
Method
Euro-nymphing through the deeper pockets; switch to dries when sedges or olives come off in autumn afternoons.
Kit
10 ft #3 nymphing rod for the deep pockets; 9 ft #4 for dries. 4 to 5 lb fluoro tippet, 12 ft leader.
Likely species
Caddisflies
Damselflies & dragonflies
Hatch timeline · tomorrowPeak at 13 Uhr
12 Uhr(now) — Autumn Olive
Stage: On emergersApproach: Emerger or dryActivity: 57%
Also:Black Midge51%Autumn Needle Fly51%
Peak emergence window8 food groups active
Peak activity at 13 Uhr — Iron Blue (Iron Blue, 9 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
Supporters see what else is on the menu.
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
1
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
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.
- Savoie AAPPMA permits.
What's coming
Plan ahead
5-day outlook
Fishing better nearby · 5
Gallery · 2
Terrain map
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · FRDR361A
The full read · show the working · for Grayling · confidence 75%
How the 0 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time50 × 13%6.5
Pressure80 × 7%5.6
Insect activity52 × 12%6.2
Conditions total= 79
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 2. Saturday im March → 3. Sunday im September
- Grayling 3. Saturday im May → 3. Sunday im September
France national rule: grayling opens 3rd Saturday of May in all waters. In 1st category (salmonid) rivers, grayling closes with the trout season on the 3rd Sunday of September. Departmental regulations may impose additional restrictions. Always check the relevant département's 2026 arrêté préfectoral.
Related guides
Booking & contacts