Lowland · Mixed · East Jutland

Lilleåen

Lilleåen terrain map

A Gudenå tributary singled out by Riverfisher as the place for really big sea trout in the system.

Poor · Brown Trout
Pheasant Tail Nymph · 14-18
Poorlive now
Not the day for it
River temperature is the limiting factor today, not the flow. This is not the day to push it. Check the thermal advice above before you head out.
80% confidence
What moved it
  • LevelProxyvia Karup Å
  • Water temp20.9°C
  • ClarityClear
Today's fly
Pheasant Tail Nymph
Pheasant Tail Nymph14-18
High-confidence seasonal pick
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Karup Å
Water temp20.9°C
ClarityClear
Weather21°C
WindSE 9 km/h
Pressure1013 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

No gauge on this water — conditions are inferred from Karup Å. The trend transfers, the absolute level does not.

Water temperature for Brown Trout
Warm — slow
21°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.
Why this works
Water at 20.9°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 11 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 3 with Pro.

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Evidence
Survey-backed · regionalModerate 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
Sea trout runRun
1
2
2
2
2
2
2
2
1
Trout seasonSeason
1
2
2
2
2
2
2
2
1
Terrestrial BeetlesHatch
2
3
3
2
Blue Winged OliveHatch
1
2
2
2
2
1
Black MidgeHatch
1
2
2
2
2
2
2
2
2
2
2
1
Summer River MidgeHatch
1
2
2
2
1

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Brown Trout fly box
SW
Small wet fly (Ke-He style)
10-14 · Small wet fly
Proven pattern for this period
Permits & access
Permit required — see local rules.
  • Fisketegn + local association permit
  • Check current sea-trout protection rules in the Gudenå system carefully — parts of the system upstream of Lilleåen are currently closed to sea-trout fishing.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 21°C — probably warm enough to stress Brown Trout . These are likely cooler.
Villestrup Å
55 km
~16°C
Brown trout · Sea trout
About this water

A Gudenå tributary singled out by Riverfisher as the place for really big sea trout in the system. Not a famous headline river in its own right, but it matters precisely because the Gudenå sea-trout story points here. Small-scale water — intimate, manageable, and with the potential for a genuinely large migratory fish. Access is association-managed. Current protection rules for sea trout in parts of the Gudenå system upstream of Lilleåen mean rules must be checked carefully before fishing.

  • Mixed
The full read · show the working · for Brown Trout · confidence 80%
How the 22 is built — score × weight = contribution
Temperature15 × 28%4.2
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity63 × 12%7.6
Limiting factor: Water temperature (20.9°C) is outside Brown Trout's preferred range (10–16°C)= 60
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Karup Åproxy
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.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Sea trout 1 March → 30 November
  • Trout 1 March → 30 November

Sea trout: Variable seasonal (2026)

Related guides
Euro Nymphingsubsurface methods
Booking & contacts