- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRHR163
Rules at a glance
- Free fishing
- Fly only
Water temperature for Brown Trout
Warm — slow17°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season. Iron Blue and CDC grannom in April; olives through May; sedges through summer evenings.
Where
Pool tails and weeded glides through the Seine-Maritime chalk-stream stretches. Intimate water — read each lie carefully.
Method
Upstream dry to spotted rising fish; long fine leader. The water reads clear — careful approach matters more than fly choice. Move slowly upstream, cast accurately, accept the result.
Kit
9 ft #4 — French karst-stream default. Floating line, 14 ft leader to 4 lb fluoro. Polarising glasses non-negotiable.
Why this works
Good — water clarity is right today, though insect activity could be better.
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
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 4 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
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
Brown Trout fly box
Permits & access
Permit required — see local rules.
- AAPPMA du Pays de Bray and local AAPPMAs share the beats on both rivers
- Fly-only parcours on several stretches
- Check current rules before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 1
Terrain map
Water quality (WFD)
The full read · show the working · for Brown Trout · confidence 90%
How the 74 is built — score × weight = contribution
Temperature59 × 28%16.5
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 74
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Arquesproxy
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.
Directions
Seasons & zones
- Trout 2nd Saturday of March → 3rd Sunday of September
- Grayling 3rd Saturday of 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.
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts
Béthune / Eaulne
Water temperature for Brown Trout
Warm — slow17°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season. Iron Blue and CDC grannom in April; olives through May; sedges through summer evenings.
Where
Pool tails and weeded glides through the Seine-Maritime chalk-stream stretches. Intimate water — read each lie carefully.
Method
Upstream dry to spotted rising fish; long fine leader. The water reads clear — careful approach matters more than fly choice. Move slowly upstream, cast accurately, accept the result.
Kit
9 ft #4 — French karst-stream default. Floating line, 14 ft leader to 4 lb fluoro. Polarising glasses non-negotiable.
Why this works
Good — water clarity is right today, though insect activity could be better.
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
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 4 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
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
Brown Trout fly box
Permits & access
Permit required — see local rules.
- AAPPMA du Pays de Bray and local AAPPMAs share the beats on both rivers
- Fly-only parcours on several stretches
- Check current rules before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 1
Terrain map
Water quality (WFD)
- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRHR163
The full read · show the working · for Brown Trout · confidence 90%
How the 74 is built — score × weight = contribution
Temperature59 × 28%16.5
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 74
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Arquesproxy
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.
Directions
Seasons & zones
- Trout 2nd Saturday of March → 3rd Sunday of September
- Grayling 3rd Saturday of 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.
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts