Rules at a glance
- Public water
- Licence required
- Fly only
Water temperature for Brown Trout
Cool — slow7°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the Castilla y León trout season — 3rd Sunday of March to 31 July. Spring olives April through May; summer sedges in evening hours; sin muerte stretches extend through autumn.
Where
Pool tails, riffle heads, and the seams behind boulders through the Segovian beats. The Eresma runs from the Sierra de Guadarrama through clear granite pocket water.
Method
Upstream dry to risers; dry-dropper through the riffles. The water reads clear — long leader, fine tippet, careful approach.
Kit
9 ft #4 — Castilian default. Floating line, 12 ft leader to 4 lb fluoro. Studded boots — granite cobble runs slick.
Likely species
Stoneflies
Hatch timeline · tomorrowPeak at 11h
12h(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 52%
Also:Black Midge49%Autumn Olive30%
Peak emergence windowWeather boost4 food groups active
Peak activity at 11h — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 4 guilds as a supporter.
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 · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
1
Large Dark OliveHatch
1
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Autumn OliveHatch
1
2
1
Brown SedgeHatch
1
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Brown Trout
Permits & access
Permit required — see local rules.
- Castilla y León licence required
- The Valsaín–La Granja stretch is the wild-trout identity of the river; lower city/agricultural beats follow different (often stocked) management
- Match the tramo to your goal before booking.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Terrain map
The full read · show the working · for Brown Trout · confidence 75%
How the 0 is built — score × weight = contribution
Temperature68 × 28%19.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity41 × 12%4.9
Conditions total= 68
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Warmer water — toward the 10–16 °C ideal band — would lift the temperature score.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout Dernier Sunday de March → 31 July
Related guides
Booking & contacts
Río Eresma
Water temperature for Brown Trout
Cool — slow7°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the Castilla y León trout season — 3rd Sunday of March to 31 July. Spring olives April through May; summer sedges in evening hours; sin muerte stretches extend through autumn.
Where
Pool tails, riffle heads, and the seams behind boulders through the Segovian beats. The Eresma runs from the Sierra de Guadarrama through clear granite pocket water.
Method
Upstream dry to risers; dry-dropper through the riffles. The water reads clear — long leader, fine tippet, careful approach.
Kit
9 ft #4 — Castilian default. Floating line, 12 ft leader to 4 lb fluoro. Studded boots — granite cobble runs slick.
Likely species
Hatch timeline · tomorrowPeak at 11h
12h(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 52%
Also:Black Midge49%Autumn Olive30%
Peak emergence windowWeather boost4 food groups active
Peak activity at 11h — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 4 guilds as a supporter.
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 · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
1
Large Dark OliveHatch
1
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Autumn OliveHatch
1
2
1
Brown SedgeHatch
1
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Brown Trout
Permits & access
Permit required — see local rules.
- Castilla y León licence required
- The Valsaín–La Granja stretch is the wild-trout identity of the river; lower city/agricultural beats follow different (often stocked) management
- Match the tramo to your goal before booking.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Terrain map
The full read · show the working · for Brown Trout · confidence 75%
How the 0 is built — score × weight = contribution
Temperature68 × 28%19.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity41 × 12%4.9
Conditions total= 68
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Warmer water — toward the 10–16 °C ideal band — would lift the temperature score.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout Dernier Sunday de March → 31 July
Related guides
Booking & contacts