- Ecology: Good
- Chemical: Unknown
WFD classification · FRDR499
Rules at a glance
- Day tickets
- Fly only
Water temperature for Grayling
Ideal13°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime. The Bienne's grayling fish well in cool karst water.
Where
Faster runs and the heads of riffles through the middle valley.
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
Good — water temperature is working for you, but time of day is the limiting factor today.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 with Pro.
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 · August 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
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Small Dark OliveHatch
2
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Grayling fly box
Permits & access
Permit required — see local rules.
- AAPPMA permits required
- Fly-only and no-kill parcours on several marked stretches
- Check the FDAAPPMA du Jura maps for closed zones.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
The Bienne river at Vaux-les-Saint-Claude, Haut-Jura, near the Gour aux Moines Terrain map
Water quality (WFD)
The full read · show the working · for Grayling · confidence 75%
How the 77 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow95 × 22%20.9
Clarity70 × 18%12.6
Feeding Time25 × 13%3.3
Pressure80 × 7%5.6
Insect activity58 × 12%7.0
Conditions total= 77
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 2nd Saturday of March → 3rd Sunday of September
- Grayling 3rd Saturday of May → 3rd Sunday of 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
Bienne
Water temperature for Grayling
Ideal13°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Autumn through November prime. The Bienne's grayling fish well in cool karst water.
Where
Faster runs and the heads of riffles through the middle valley.
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
Good — water temperature is working for you, but time of day is the limiting factor today.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 with Pro.
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 · August 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
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Small Dark OliveHatch
2
3
3
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Grayling fly box
Permits & access
Permit required — see local rules.
- AAPPMA permits required
- Fly-only and no-kill parcours on several marked stretches
- Check the FDAAPPMA du Jura maps for closed zones.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
The Bienne river at Vaux-les-Saint-Claude, Haut-Jura, near the Gour aux Moines Terrain map
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · FRDR499
The full read · show the working · for Grayling · confidence 75%
How the 77 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow95 × 22%20.9
Clarity70 × 18%12.6
Feeding Time25 × 13%3.3
Pressure80 × 7%5.6
Insect activity58 × 12%7.0
Conditions total= 77
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 2nd Saturday of March → 3rd Sunday of September
- Grayling 3rd Saturday of May → 3rd Sunday of 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