Water temperature for Marble Trout
Warm — slow23°C est.ideal 8–13°C
0°14°28°
How to fish it · for Marble Trout
When
Low light again — early and late in the day, when marbles slide up from the deep glides to feed. A tagging programme has run here for years, so a marked fish isn't unusual; report it if you catch one.
Where
The deepest, slowest water on the reach — glide heads, bedrock sills, anywhere the current stacks against structure. They don't so much share the water with brown trout as tolerate them in it.
Method
Streamer on an intermediate or slow-sink line, worked slowly through the deep water. Barbless single hook, release with the fish still in the net.
Kit
9 to 10 ft #6/7, intermediate line, 8 to 10 lb fluoro. Wet net for handling.
Why this works
Water at 22.7°C. This is the line where catch-and-release kills marble trout. Do not fish for them today.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 2 with Pro.
Start free trial14-day free trial. Cancel anytime.
Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Large Dark OliveHatch
1
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Autumn OliveHatch
1
2
1
GrannomHatch
1
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Marble Trout fly box
Permits & access
Permit required — see local rules.
- No-kill reserve — mandatory catch-and-release, barbless single hook, maximum three flies
- Daily no-kill permit required, purchased through the Consorzio Pesca Valle d'Aosta.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 2
Probably above the Marble Trout safety line — these are likely cooler, but carry a thermometer.
The full read · show the working · for Marble Trout · confidence 90%
How the 10 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow45 × 22%9.9
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity42 × 12%5.0
Limiting factor: Water temperature (22.7°C) is outside Marble Trout's preferred range (8–13°C)= 48
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
What would change the calculation
Cooler water — back toward the 8–13 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 2026-03-29 → 2026-10-14
- Grayling 2026-03-29 → 2026-10-14
All grayling must be returned — retention is prohibited here.
- Marble trout 2026-03-29 → 2026-10-14
Related guides
Booking & contacts
Dora Baltea (No-Kill, Chambave-Verrayes)
Water temperature for Marble Trout
Warm — slow23°C est.ideal 8–13°C
0°14°28°
How to fish it · for Marble Trout
When
Low light again — early and late in the day, when marbles slide up from the deep glides to feed. A tagging programme has run here for years, so a marked fish isn't unusual; report it if you catch one.
Where
The deepest, slowest water on the reach — glide heads, bedrock sills, anywhere the current stacks against structure. They don't so much share the water with brown trout as tolerate them in it.
Method
Streamer on an intermediate or slow-sink line, worked slowly through the deep water. Barbless single hook, release with the fish still in the net.
Kit
9 to 10 ft #6/7, intermediate line, 8 to 10 lb fluoro. Wet net for handling.
Why this works
Water at 22.7°C. This is the line where catch-and-release kills marble trout. Do not fish for them today.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 2 with Pro.
Start free trial14-day free trial. Cancel anytime.
Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Large Dark OliveHatch
1
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Autumn OliveHatch
1
2
1
GrannomHatch
1
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Marble Trout fly box
Permits & access
Permit required — see local rules.
- No-kill reserve — mandatory catch-and-release, barbless single hook, maximum three flies
- Daily no-kill permit required, purchased through the Consorzio Pesca Valle d'Aosta.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 2
Probably above the Marble Trout safety line — these are likely cooler, but carry a thermometer.
The full read · show the working · for Marble Trout · confidence 90%
How the 10 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow45 × 22%9.9
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity42 × 12%5.0
Limiting factor: Water temperature (22.7°C) is outside Marble Trout's preferred range (8–13°C)= 48
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
What would change the calculation
Cooler water — back toward the 8–13 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 2026-03-29 → 2026-10-14
- Grayling 2026-03-29 → 2026-10-14
All grayling must be returned — retention is prohibited here.
- Marble trout 2026-03-29 → 2026-10-14
Related guides
Booking & contacts