Chalk · Normandy / Seine-Maritime (Dieppe area)

Arques

Arques terrain map
Terrain map

The Arques is a quiet Normandy chalk stream near Dieppe that holds a genuine sea trout run alongside its resident brown trout and grayling — 28 declared sea trout in 2024, which places it ahead of several more famous French migratory rivers.

Poor · Brown Trout
Spent Spinner · 16-20
Poorlive now
Not the day for it
River temperature is the limiting factor today, not the flow. This is not the day to push it. Check the thermal advice above before you head out.
90% confidence
What moved it
  • LevelLiveTrend only — level not reported
  • Water temp23.5°C
  • ClarityClear
Today’s fly
Spent Spinner
Spent Spinner16-20
Upstream dry
Conditions on the water
Live gauge
Level
Steady
Live
Trend only — level not reported
Water temp23.5°C
ClarityClear
Weather28°C
WindNE 15 km/h
Pressure1017 hPa
Rain · recent0.2 mm
Rain · ahead5.7 mm

Live readings only. Trends shown where the gauge supports them.

Water temperature for brown trout
Warm — slow
23.5°Cideal 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 chalk-stream stretches around Dieppe. The Arques is intimate water; read each lie.
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
⛔ Water at 23.5°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey

Hatch predictions

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Evidence
Survey-backed · regionalModerate confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Sea trout runRun
1
2
2
2
2
2
1
Trout seasonSeason
1
2
2
2
2
2
1
Grayling seasonSeason
1
2
2
2
2
2
2
1
Brown SedgeHatch
2
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Blue Winged OliveHatch
2
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
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.
  • Cartes de pêche AAPPMA
  • Sections en eaux privées sur certains secteurs.
What's coming
Plan ahead
5-day outlook
Water here at 23.5°C. Nothing cooler within range.
About this water

The Arques is a quiet Normandy chalk stream near Dieppe that holds a genuine sea trout run alongside its resident brown trout and grayling — 28 declared sea trout in 2024, which places it ahead of several more famous French migratory rivers. The chalk character gives it stable, clear water and prolific invertebrate life. Small olives and evening sedges sustain selective dry-fly fishing for brown trout through the season. Sea trout enter from the estuary and run on spate water, providing a secondary but credible target from summer through autumn.

  • Chalk
Water quality (WFD)
  • Ecology: Moderate
  • Chemical: Unknown

WFD classification · FRHR166

The full read · show the working · for brown trout · confidence 90%
How the 0 is built — score × weight = contribution
Temperature0 × 28%0.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity54 × 12%6.5
Limiting factor: Water temperature (23.5°C) is outside Brown Trout's preferred range (10–16°C)= 55
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
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.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Sea trout25 April → 25 October
  • Trout2nd Saturday of March → 3rd Sunday of September
  • Grayling3rd 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: Open (2026) — Credible secondary sea trout river. 28 declared rod catches in 2024 — better than many historic glamour rivers.

Related guides
Chalkstream Playbookchalk stream tacticsGrayling Playbookgrayling tacticsPyrenees PlaybookFrench rivers
Booking & contacts