Freestone · Mixed · Primorsko-goranska / Gorski Kotar, HR

Kupa (Upper / Risnjak NP)

Strict conservation fly fishery within Risnjak National Park — catch-and-release only, barbless hooks, no boats, no night fishing.

Today · About as good as it gets
Black Midge
Forecast · Today
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
75% projected
Today's fly
Black Midge
Black Midge
Conditions on the water · Today
Live gauge
Level
Steady
0.44 m
Water temp7.8°C
ClarityClear
Weather10°C
WindN 8 km/h
Pressure1026 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Grayling
Ideal
8°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Midday window — grayling feed best from late morning into early afternoon.
Where
Work runs and glides — grayling shoal in the bottom third of the water column.
Method
Tight-line nymph the bottom third with weighted patterns.
Kit
10 ft #3 rod, floating line, long leader to 4 lb fluoro for nymphs.
Why this works
Excellent — water temperature is working for you, but time of day is the limiting factor today. Grayling is active in the cooler margins of the season.
Likely species
Mayflies
Stoneflies
Damselflies & dragonflies
Gammarids
Hatch timeline · todayPeak at 10am

12pm(now) — Black Midge

Stage: On emergersApproach: Emerger or dryActivity: 54%
Also:Autumn Needle Fly40%Autumn Olive36%
Peak emergence window6 food groups active

Peak activity at 10am — Black Midge (Black Midge, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds as a supporter.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

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
Grayling seasonSeason
1
2
2
2
2
1
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1

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

Ranked for today
Grayling fly box

Best represented by the Gacka and similar waters: clear, stable limestone rivers where dry fly, nymph and streamer all matter.

Small Perdigón
Small Perdigón
Hook 14–18 · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
  • Croatian fishing licence plus local permit
  • Risnjak park section is catch-and-release, fly only, single barbless hook, no boats, and no night fishing
  • Park entrance also applies.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Kupa (Risnjak National Park)
9.0 km
Brown trout · Grayling · Hucho
Kupica
13 km
Brown trout · Grayling
Curak
17 km
Brown trout
River Kolpa
27 km
79
Brown trout · Grayling · Hucho
Bloško jezero
41 km
Carp · Pike
Gallery · 1
  1. Kupa (Risnjak National Park) — IMG 20180713 163857(fixed)
    IMG 20180713 163857(fixed)
About this water

Strict conservation fly fishery within Risnjak National Park — catch-and-release only, barbless hooks, no boats, no night fishing. The upper Kupa flows through dense Gorski Kotar forest with brown trout and grayling in classic upland freestone water. Good hatches of olives, caddis and stoneflies through spring and summer. Euro nymphing and dry fly both productive. Deeper stretches also hold huchen — strictly regulated trophy fishery in winter.

  • Mixed
Water quality (WFD)
  • Ecology: Good
  • Chemical: Unknown

WFD classification · HRCSRN0481_001

The full read · show the working · for Grayling · confidence 75%
How the 80 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time20 × 13%2.6
Pressure80 × 7%5.6
Insect activity47 × 12%5.6
Conditions total= 75
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 16 May → 30 September
  • Grayling 16 May → 15 October

    Conflicting sources for Kupa grayling season: Risnjak National Park (upper Kupa, C&R) lists grayling 16 May – 15 October; Kupa Fly Fishing operator lists 1 April – 15 October. Use the stricter May window until the specific beat/concession confirms otherwise. Croatian national rule: one rod, artificial fly or lure only in permanent grayling habitats.

    Prime sport 1 August → 15 October

    • 16 May → 15 Oct · Artificial fly or artificial lure
  • Hucho 1 October → 28 February
Related guides
Hucho / Danube Salmonspecialist apex-predator guideGrayling Playbookgrayling tacticsEuro Nymphingsubsurface methods
Booking & contacts