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
Rules at a glance
- Public water
- Licence required
Water temperature for Brown Trout
Warm — slow20°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.
Why this works
Water at 20.4°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 6pm
Hatch predictions
Today's headline hatch shown — see all 7 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds 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
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
Cooler water nearby · 1
Water here around 20°C — probably warm enough to stress Brown Trout . These are likely cooler.
Gallery · 1
Terrain map
About this water
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature20 × 28%5.6
Flow95 × 22%20.9
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity65 × 12%7.8
Limiting factor: Water temperature (20.4°C) is outside Brown Trout's preferred range (10–16°C)= 67
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.
Directions
Seasons & zones
- Trout 1 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
Main western Pyrenean Ebro tributary crossing Aragón into Navarra.
Water temperature for Brown Trout
Warm — slow20°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.
Why this works
Water at 20.4°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 6pm
Hatch predictions
Today's headline hatch shown — see all 7 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 guilds 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
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
Cooler water nearby · 1
Water here around 20°C — probably warm enough to stress Brown Trout . These are likely cooler.
Gallery · 1
Terrain map
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 80%
How the 0 is built — score × weight = contribution
Temperature20 × 28%5.6
Flow95 × 22%20.9
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity65 × 12%7.8
Limiting factor: Water temperature (20.4°C) is outside Brown Trout's preferred range (10–16°C)= 67
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.
Directions
Seasons & zones
- Trout 1 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