Freestone · Mixed · Haute-Savoie / Savoie

Arly

A wide alpine river flows over a gravel bed between forested banks, with mountains rising in the background near Césarches, Savoie, France.
Contributor photo

The River Arly near Césarches, Savoie

Florian Pépellin CC BY-SA 4.0

The Arly comes down off the Aravis fast and cold, gathering snowmelt through spring before slowing enough in its middle reaches to become properly fishable.

Good · Brown Trout
Small Perdigón · 16-20
Goodlive now
A proper day on the water
Low and clear — careful approach country. Stay small, stay accurate.
90% confidence
What moved it
  • LevelDry recentlyNo gauge reading
  • Water temp17.8°C
  • ClarityClear
Today’s fly
Small Perdigón
Small Perdigón16-20
Euro-nymph
Conditions on the water
Estimate
Level
Dry recently
No gauge reading
Water temp17.8°C
ClarityClear
Weather16°C
WindNW 4 km/h
Pressure1019 hPa
Rain · recent0.6 mm
Rain · ahead29.3 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for brown trout
Warm — slow
18°C est.ideal 1016°C
0°14°28°
How to fish it · for brown trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
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 3 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 2 with Pro.

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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
Trout seasonSeason
1
2
2
2
2
2
1
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Brown Trout fly box
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
  1. A wide alpine river flows over a gravel bed between forested banks, with mountains rising in the background near Césarches, Savoie, France.
    The River Arly near Césarches, Savoie
  2. Terrain map of the venue
    Terrain map
About this water

The Arly comes down off the Aravis fast and cold, gathering snowmelt through spring before slowing enough in its middle reaches to become properly fishable. You want it in late June through July — that short window after the runoff has cleared and before the summer drawdown bites. The fish are wild browns, small but vigorous, in pocket water and short plunge pools that reward a short line and a heavy nymph. Don't come expecting length; this is an intimate river in a big landscape, and the pleasure is in reading the water rather than covering it. The upper valley around Ugine is the postcard country; the lower reaches towards Albertville warm by August and the fishing moves upstream. Bring a 9ft 4-weight for the middle river and a shorter rod for the headwaters.

  • Mixed
Water quality (WFD)
  • EcologyGood
  • ChemicalUnknown

WFD classification · FRDR362A

The full read · show the working · for brown trout · confidence 90%
How the 68 is built — score × weight = contribution
Temperature60 × 28%16.8
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity51 × 12%6.1
Conditions total= 68
Can you trust it?
Water temperatureair-to-water estimateestimated
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.
Directions
Seasons & zones
  • Trout2nd Saturday of March → 3rd Sunday of September
Related guides
Booking & contacts