- Ecology: Good
- Chemical: Unknown
WFD classification · ES017MSPFES002MAR002380
Water temperature for Brown Trout
Warm — slow20°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 20.3°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 2 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
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.
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
Trout seasonSeason
1
1
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.
- Se requiere licencia de pesca del Gobierno de Navarra
- Las normas de agua fronteriza y de tramo nominal son relevantes aquí, así que comprueba el tramo exacto y la estructura de permisos antes de viajar
- No trates este coto como un destino de planificación para salmón.
What's coming
Plan ahead
5-day outlook
Water here around 20°C. Nothing cooler within range — carry a thermometer.
Water quality (WFD)
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature21 × 28%5.9
Flow95 × 22%20.9
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity64 × 12%7.7
Limiting factor: Water temperature (20.3°C) is outside Brown Trout's preferred range (10–16°C)= 68
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Bidasoaproxy
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.
Directions
Seasons & zones
- Trout 1 May → 30 June
RSS Baztan–Bidasoa basin (9,898 permits in 2026 — largest allocation in Navarra). All catch-and-release. Extendable to 15 Jul by resolution. Daily basin permit required. IMPORTANT: the Tramo Salmonero (presa de Fundiciones de Bera to Endarlatsa) is CLOSED for all of 2026 — this entry covers trout fishing in the broader Baztan–Bidasoa basin, not the salmon beat.
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts
Bidasoa tributaries (Navarra side)
Water temperature for Brown Trout
Warm — slow20°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 20.3°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 2 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
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.
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
Trout seasonSeason
1
1
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.
- Se requiere licencia de pesca del Gobierno de Navarra
- Las normas de agua fronteriza y de tramo nominal son relevantes aquí, así que comprueba el tramo exacto y la estructura de permisos antes de viajar
- No trates este coto como un destino de planificación para salmón.
What's coming
Plan ahead
5-day outlook
Water here around 20°C. Nothing cooler within range — carry a thermometer.
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · ES017MSPFES002MAR002380
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature21 × 28%5.9
Flow95 × 22%20.9
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity64 × 12%7.7
Limiting factor: Water temperature (20.3°C) is outside Brown Trout's preferred range (10–16°C)= 68
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Bidasoaproxy
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.
Directions
Seasons & zones
- Trout 1 May → 30 June
RSS Baztan–Bidasoa basin (9,898 permits in 2026 — largest allocation in Navarra). All catch-and-release. Extendable to 15 Jul by resolution. Daily basin permit required. IMPORTANT: the Tramo Salmonero (presa de Fundiciones de Bera to Endarlatsa) is CLOSED for all of 2026 — this entry covers trout fishing in the broader Baztan–Bidasoa basin, not the salmon beat.
Sea trout: Variable seasonal (2026)
Related guides
Booking & contacts