Rules at a glance
- Public water
- Licence required
- Fly only
Water temperature for Brown Trout
Cool — slow5°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.
Likely species
Gammarids
Hatch timeline · todayQuiet day
12h(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 17%
Low insect activity predicted today
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 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
Late March BrownHatch
2
3
2
Large Brook DunHatch
2
3
2
Large StoneflyHatch
2
3
2
Olive UprightHatch
2
3
3
2
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
- Montaña Palentina — check Fuentes Carrionas natural park rules.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
The full read · show the working · for Brown Trout · confidence 75%
How the 0 is built — score × weight = contribution
Temperature30 × 28%8.4
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time50 × 13%6.5
Pressure80 × 7%5.6
Insect activity35 × 12%4.2
Conditions total= 59
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 Castillería
Water temperature for Brown Trout
Cool — slow5°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.
Likely species
Hatch timeline · todayQuiet day
12h(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 17%
Low insect activity predicted today
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 2 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
Late March BrownHatch
2
3
2
Large Brook DunHatch
2
3
2
Large StoneflyHatch
2
3
2
Olive UprightHatch
2
3
3
2
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
- Montaña Palentina — check Fuentes Carrionas natural park rules.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
The full read · show the working · for Brown Trout · confidence 75%
How the 0 is built — score × weight = contribution
Temperature30 × 28%8.4
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time50 × 13%6.5
Pressure80 × 7%5.6
Insect activity35 × 12%4.2
Conditions total= 59
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