- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRDR555A
Rules at a glance
- Day tickets
Water temperature for Brown Trout
Warm — slow22°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season — once snowmelt drops. Mont Blanc-fed glacial influence means the Arve runs cold and clear once meltwater eases. Best from late June into autumn close.
Where
Pool tails and pocket water through the Haute-Savoie valley. Glacial-fed water reads cold and clear.
Method
Upstream dry to risers; dry-dropper through the riffles. The water reads clear — long leader, fine tippet. Move slowly, cast accurately.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Why this works
Water at 22.2°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayPeak at 6pm
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
Hatch predictions
Top prey shown — see all 2 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
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
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Arve Terrain map
Water quality (WFD)
The full read · show the working · for Brown Trout · confidence 90%
How the 10 is built — score × weight = contribution
Temperature5 × 28%1.4
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Limiting factor: Water temperature (22.2°C) is outside Brown Trout's preferred range (10–16°C)= 58
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Giffreproxy
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
Related guides
Booking & contacts
Clubs & associations
Arve
Water temperature for Brown Trout
Warm — slow22°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season — once snowmelt drops. Mont Blanc-fed glacial influence means the Arve runs cold and clear once meltwater eases. Best from late June into autumn close.
Where
Pool tails and pocket water through the Haute-Savoie valley. Glacial-fed water reads cold and clear.
Method
Upstream dry to risers; dry-dropper through the riffles. The water reads clear — long leader, fine tippet. Move slowly, cast accurately.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Why this works
Water at 22.2°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayPeak at 6pm
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
Hatch predictions
Top prey shown — see all 2 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
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
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Arve Terrain map
Water quality (WFD)
- Ecology: Moderate
- Chemical: Unknown
WFD classification · FRDR555A
The full read · show the working · for Brown Trout · confidence 90%
How the 10 is built — score × weight = contribution
Temperature5 × 28%1.4
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Limiting factor: Water temperature (22.2°C) is outside Brown Trout's preferred range (10–16°C)= 58
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Giffreproxy
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
Related guides
Booking & contacts
Clubs & associations