Karst Spring · Limestone · Castilla y León, ES

Río Ucero

Río Ucero — Cañón del Río Lobos Soria con Ermita de San Bartolomé de Ucero

A short, picturesque Duero tributary rising at the spring of Ucero and falling through the Cañón del Río Lobos before joining the Duero near El Burgo de Osma.

Today · Closed season
Brown Sedge Pupa
Forecast · Today
Closed season
Out of season. Plenty of other water available now.
90% projected
Today's fly
Brown Sedge Pupa
Brown Sedge Pupa
Conditions on the water · Today
Estimate
Level
Dry recently
No gauge reading
Water temp14.6°C
ClarityClear
Weather24°C
WindN 9 km/h
Pressure1021 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for Brown Trout
Ideal
15°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.
Hatch timeline · todayPeak at 2pm

12pm(now) — Reed Smut

Stage: On emergersApproach: Emerger or dryActivity: 76%
Also:Flying Ants61%Brown Sedge56%Pale Watery52%
Peak emergence windowWeather boost10 food groups active

Peak activity at 2pm — Brown Sedge (Brown Sedge, Weather boost)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds with Pro.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 4 with Pro.

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Evidence
Survey-backed · regionalHigh confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
1
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Small Dark OliveHatch
2
3
3
3
2

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.
  • Castilla y León licence required
  • Cañón del Río Lobos natural park — verify access rules and any closed sections before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Upper Río Duero
35 km
0
Brown trout
Río Revinuesa
43 km
0
Brown trout
Río Riaza
52 km
0
Brown trout
Río Arlanza
41 km
Brown trout
Río Abión
43 km
Brown trout
Gallery · 2
  1. Río Ucero — Cañón del Río Lobos Soria con Ermita de San Bartolomé de Ucero
    Cañón del Río Lobos Soria con Ermita de San Bartolomé de Ucero
  2. Terrain map of the venue
    Terrain map
About this water

A short, picturesque Duero tributary rising at the spring of Ucero and falling through the Cañón del Río Lobos before joining the Duero near El Burgo de Osma. The Ucero combines karst clarity and a dramatic gorge setting with reliable wild brown trout fishing. The middle reaches between Ucero village and El Burgo offer the most accessible water; the gorge itself is partially within the natural park and requires careful access checks.

  • Limestone
The full read · show the working · for Brown Trout · confidence 90%
How the 0 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity58 × 12%7.0
Conditions total= 78
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Last Sunday of March → 31 July
Related guides
Pyrenees PlaybookSpanish riversEuro Nymphingsubsurface methods
Booking & contacts