- Ecology: Good
- Chemical: Unknown
WFD classification · FRDR484
Rules at a glance
- Day tickets
Water temperature for Chub
Ideal18.7°Cideal 14–22°C
0°14°28°
How to fish it · for Chub
When
Mars à octobre
Where
The Ain from Varambon to the Rhône confluence flows through limestone with multiple designated no-kill beats and fly-only sections.
Why this works
Good — water temperature is right today, though time of day could be better.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 8 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 3 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 3 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
Grayling seasonSeason
1
2
2
2
1
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Chub fly box
Hook 8–10 weighted · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- Carte de pêche AAPPMA.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
The River Ain near Villieu-Loyes-Mollon, on the lower Ain plain Terrain map
Water quality (WFD)
The full read · show the working · for Chub · confidence 75%
How the 78 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity70 × 18%12.6
Feeding Time50 × 13%6.5
Pressure85 × 7%6.0
Insect activity61 × 12%7.3
Conditions total= 78
Can you trust it?
Water temperaturelive gauge readinggauge
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.
- Coarse 2nd Saturday of March → 3rd Sunday of September
Chub has no national closed season of its own in France — on a 1st-category (salmonid) reach like this, ALL fishing (any species, any method) is prohibited outside the water's own open season (Code de l'environnement Art. R436-6), so chub simply inherits the trout/grayling season rather than following a separate coarse-fish law.
Related guides
Booking & contacts
Ain (lower / Plaine de l'Ain)
Water temperature for Chub
Ideal18.7°Cideal 14–22°C
0°14°28°
How to fish it · for Chub
When
Mars à octobre
Where
The Ain from Varambon to the Rhône confluence flows through limestone with multiple designated no-kill beats and fly-only sections.
Why this works
Good — water temperature is right today, though time of day could be better.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 8 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 3 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 3 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
Grayling seasonSeason
1
2
2
2
1
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Chub fly box
Hook 8–10 weighted · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- Carte de pêche AAPPMA.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
The River Ain near Villieu-Loyes-Mollon, on the lower Ain plain Terrain map
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · FRDR484
The full read · show the working · for Chub · confidence 75%
How the 78 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity70 × 18%12.6
Feeding Time50 × 13%6.5
Pressure85 × 7%6.0
Insect activity61 × 12%7.3
Conditions total= 78
Can you trust it?
Water temperaturelive gauge readinggauge
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.
- Coarse 2nd Saturday of March → 3rd Sunday of September
Chub has no national closed season of its own in France — on a 1st-category (salmonid) reach like this, ALL fishing (any species, any method) is prohibited outside the water's own open season (Code de l'environnement Art. R436-6), so chub simply inherits the trout/grayling season rather than following a separate coarse-fish law.
Related guides
Booking & contacts