Water temperature for Brown Trout
Warm — slow23°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
Water at 23.4°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 5 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
See what else is on the menu with Pro.
Start free trial14-day free trial. Cancel anytime.
Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
1
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.
- Catalan fishing licence (llicència de pesca) required
- Upper Segre carries multiple ZPCs (Zones de Pesca Controlada) — La Seu d'Urgell, Bellver, Martinet, Oliana area — each with its own permit allocation, season class (alta muntanya vs baixa muntanya), and method rules (amb mort vs sense mort)
- Confirm the exact tramo and current Generalitat Resolució de vedes before planning.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Probably above the Brown Trout safety line — these are likely cooler, but carry a thermometer.
The full read · show the working · for Brown Trout · confidence 90%
How the 2 is built — score × weight = contribution
Temperature1 × 28%0.3
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity40 × 12%4.8
Limiting factor: Water temperature (23.4°C) is outside Brown Trout's preferred range (10–16°C)= 53
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
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
- Trout depends on Catalan ZPC class → depends on Catalan ZPC class
Related guides
Booking & contacts
Río Segre
Water temperature for Brown Trout
Warm — slow23°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
Water at 23.4°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 5 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
See what else is on the menu with Pro.
Start free trial14-day free trial. Cancel anytime.
Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
1
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.
- Catalan fishing licence (llicència de pesca) required
- Upper Segre carries multiple ZPCs (Zones de Pesca Controlada) — La Seu d'Urgell, Bellver, Martinet, Oliana area — each with its own permit allocation, season class (alta muntanya vs baixa muntanya), and method rules (amb mort vs sense mort)
- Confirm the exact tramo and current Generalitat Resolució de vedes before planning.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Probably above the Brown Trout safety line — these are likely cooler, but carry a thermometer.
The full read · show the working · for Brown Trout · confidence 90%
How the 2 is built — score × weight = contribution
Temperature1 × 28%0.3
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity40 × 12%4.8
Limiting factor: Water temperature (23.4°C) is outside Brown Trout's preferred range (10–16°C)= 53
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
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
- Trout depends on Catalan ZPC class → depends on Catalan ZPC class
Related guides
Booking & contacts