High-altitude side valleys of the Valais holding small mountain streams with wild brown trout. Very short season—typically June to September. Intimate pocket water with tight-line nymphing.
- Granite
Water temperature for brown trout
Warm — slow18°C est.ideal 10–16°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 working for you, but time of day is the limiting factor today.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 5 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
ModelledModerate confidence
Modelled from regional ecology — no survey or occurrence data for this water 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
1
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2
Yellow SallyHatch
2
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.
- Valais Canton high-altitude streams
- Patent (Valais) + permit required
- Remote locations.
What's coming
Plan ahead
5-day outlook
Other water nearby · 3
About this water
The full read · show the working · for brown trout · confidence 75%
How the 69 is built — score × weight = contribution
Temperature62 × 28%17.4
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity53 × 12%6.4
Conditions total= 69
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Arc (Bessans reach)proxy
Prey activitymodelled from regional profilemodelled
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
Seasons & zones
- TroutJune → 30 September
Related guides
Booking & contacts
Valais Alpine Streams
Terrain map
High-altitude side valleys of the Valais holding small mountain streams with wild brown trout.
Water temperature for brown trout
Warm — slow18°C est.ideal 10–16°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 working for you, but time of day is the limiting factor today.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 5 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
ModelledModerate confidence
Modelled from regional ecology — no survey or occurrence data for this water 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
1
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2
Yellow SallyHatch
2
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.
- Valais Canton high-altitude streams
- Patent (Valais) + permit required
- Remote locations.
What's coming
Plan ahead
5-day outlook
Other water nearby · 3
About this water
High-altitude side valleys of the Valais holding small mountain streams with wild brown trout. Very short season—typically June to September. Intimate pocket water with tight-line nymphing.
- Granite
The full read · show the working · for brown trout · confidence 75%
How the 69 is built — score × weight = contribution
Temperature62 × 28%17.4
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity53 × 12%6.4
Conditions total= 69
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Arc (Bessans reach)proxy
Prey activitymodelled from regional profilemodelled
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
Seasons & zones
- TroutJune → 30 September
Related guides
Booking & contacts