- Ecology: Good
- Chemical: Unknown
WFD classification · ES018MSPFES090MAR000200
Rules at a glance
- Public water
- Licence required
Water temperature for Brown Trout
Warm — slow21°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 21.2°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Sub-surface · on the nymphunder the surface
Hatch predictions
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh 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
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.
- Cantabrian fishing licence required
- Mixed-geology water and annex-driven rules make exact stretch checks important before travel.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 21°C — probably warm enough to stress Brown Trout . These are likely cooler.
Gallery · 2
Abra del Pas Terrain map
Water quality (WFD)
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature12 × 28%3.4
Flow28 × 22%6.2
Clarity15 × 18%2.7
Feeding Time45 × 13%5.9
Pressure80 × 7%5.6
Insect activity50 × 12%6.0
Limiting factor: Water temperature (21.2°C) is outside Brown Trout's preferred range (10–16°C)= 30
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.
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout third Sunday of March → 31 July
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts
Pas
Water temperature for Brown Trout
Warm — slow21°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 21.2°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Sub-surface · on the nymphunder the surface
Hatch predictions
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh 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
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.
- Cantabrian fishing licence required
- Mixed-geology water and annex-driven rules make exact stretch checks important before travel.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 21°C — probably warm enough to stress Brown Trout . These are likely cooler.
Gallery · 2
Abra del Pas Terrain map
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · ES018MSPFES090MAR000200
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature12 × 28%3.4
Flow28 × 22%6.2
Clarity15 × 18%2.7
Feeding Time45 × 13%5.9
Pressure80 × 7%5.6
Insect activity50 × 12%6.0
Limiting factor: Water temperature (21.2°C) is outside Brown Trout's preferred range (10–16°C)= 30
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.
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout third Sunday of March → 31 July
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts