- Ecology: Good
- Chemical: Unknown
WFD classification · ES018MSPFES175MAR001440
Rules at a glance
- Public water
- Licence required
Water temperature for Brown Trout
Warm — slow22°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 21.6°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
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 · 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
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
Beats · 1
Llantrales · 3.3 kmTrout permit
Trout permit stretch — Puente Agüera to Llantrales escuela.
Beat detail
Daily permit required, keep within bag limits
Upstream: Puente Agüera
Downstream: Llantrales escuela
Permits & access
Free state water
State rod licence required for trout / salmon as applicable.
- Asturian fishing licence required
- In 2026 many trout waters run to 15 August, but salmon zones, mountain zones, tramos sin muerte, and border stretches can differ
- Check local coto and tramo rules before fishing.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Water quality (WFD)
The full read · show the working · for Brown Trout · confidence 80%
How the 17 is built — score × weight = contribution
Temperature9 × 28%2.5
Flow15 × 22%3.3
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity22 × 12%2.6
Limiting factor: Water temperature (21.6°C) is outside Brown Trout's preferred range (10–16°C)= 38
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
Related guides
Booking & contacts
Río Cubia
Water temperature for Brown Trout
Warm — slow22°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 21.6°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
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 · 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
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
Beats · 1
Llantrales · 3.3 kmTrout permit
Trout permit stretch — Puente Agüera to Llantrales escuela.
Beat detail
Daily permit required, keep within bag limits
Upstream: Puente Agüera
Downstream: Llantrales escuela
Permits & access
Free state water
State rod licence required for trout / salmon as applicable.
- Asturian fishing licence required
- In 2026 many trout waters run to 15 August, but salmon zones, mountain zones, tramos sin muerte, and border stretches can differ
- Check local coto and tramo rules before fishing.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · ES018MSPFES175MAR001440
The full read · show the working · for Brown Trout · confidence 80%
How the 17 is built — score × weight = contribution
Temperature9 × 28%2.5
Flow15 × 22%3.3
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity22 × 12%2.6
Limiting factor: Water temperature (21.6°C) is outside Brown Trout's preferred range (10–16°C)= 38
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
Related guides
Booking & contacts