Main western Pyrenean Ebro tributary crossing Aragón into Navarra. Key trout reaches sit around Yesa and the pre-Pyrenean corridor, where bigger-water nymphing and caddis-driven dry-fly windows define the main trout interest.
- Mixed
Water temperature for brown trout
Warm — slow22°C est.ideal 10–16°C
0°14°28°
How to fish it · for brown trout
When
Through the Navarrese trout season. Spring olives April through May; sedges through summer; small dark flies into the autumn close.
Where
Pool tails and the seams behind boulders through the upper Aragón valley. Pyrenean piedmont character — clear water, classic Iberian wild brown trout water.
Method
Upstream dry to risers; dry-dropper through the riffles. The Aragón runs clear Pyrenean water — long leader, fine tippet.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Hatch timeline · todayQuiet day
Hatch predictions
See the full hour-by-hour hatch timeline 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
Records-basedModerate confidence
Based on species-occurrence records, not local invertebrate surveys.
Through the year
0–3 scale · July 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
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
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.
- Gobierno de Navarra fishing licence required
- Yesa reservoir regulates flow downstream, and the exact tramo and permit structure should be checked in the current official Navarra calendar before travel.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
About this water
The full read · show the working · for brown trout · confidence 90%
How the 0 is built — score × weight = contribution
Temperature4 × 28%1.1
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity44 × 12%5.3
Limiting factor: Water temperature (22.4°C) is outside Brown Trout's preferred range (10–16°C)= 51
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
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.
Directions
Seasons & zones
- Trout1 May → 30 June
The Aragón straddles Navarra and Aragón communities. Upper sections (Jaca area) may follow Aragonese regulations. Navarran sections fall under RSS rules — all catch-and-release, daily basin permit required. Below Yesa reservoir the river changes character: regulated tailwater flow. Check tramo-specific status for the exact stretch.
Related guides
Booking & contacts
Río Aragón
Terrain map
Main western Pyrenean Ebro tributary crossing Aragón into Navarra.
Water temperature for brown trout
Warm — slow22°C est.ideal 10–16°C
0°14°28°
How to fish it · for brown trout
When
Through the Navarrese trout season. Spring olives April through May; sedges through summer; small dark flies into the autumn close.
Where
Pool tails and the seams behind boulders through the upper Aragón valley. Pyrenean piedmont character — clear water, classic Iberian wild brown trout water.
Method
Upstream dry to risers; dry-dropper through the riffles. The Aragón runs clear Pyrenean water — long leader, fine tippet.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Hatch timeline · todayQuiet day
Hatch predictions
See the full hour-by-hour hatch timeline 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
Records-basedModerate confidence
Based on species-occurrence records, not local invertebrate surveys.
Through the year
0–3 scale · July 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
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
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.
- Gobierno de Navarra fishing licence required
- Yesa reservoir regulates flow downstream, and the exact tramo and permit structure should be checked in the current official Navarra calendar before travel.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
About this water
Main western Pyrenean Ebro tributary crossing Aragón into Navarra. Key trout reaches sit around Yesa and the pre-Pyrenean corridor, where bigger-water nymphing and caddis-driven dry-fly windows define the main trout interest.
- Mixed
The full read · show the working · for brown trout · confidence 90%
How the 0 is built — score × weight = contribution
Temperature4 × 28%1.1
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity44 × 12%5.3
Limiting factor: Water temperature (22.4°C) is outside Brown Trout's preferred range (10–16°C)= 51
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
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.
Directions
Seasons & zones
- Trout1 May → 30 June
The Aragón straddles Navarra and Aragón communities. Upper sections (Jaca area) may follow Aragonese regulations. Navarran sections fall under RSS rules — all catch-and-release, daily basin permit required. Below Yesa reservoir the river changes character: regulated tailwater flow. Check tramo-specific status for the exact stretch.
Related guides
Booking & contacts