Mayflies
Stoneflies
Caddisflies
Damselflies & dragonflies
Gammarids
- Ecology: Good
- Chemical: Unknown
WFD classification · HRCSRN0130_001
Rules at a glance
- Permit required
Water temperature for Grayling
Ideal9°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 — conditions well-balanced, with time of day particularly in your favour.
Likely species
Caddisflies
Damselflies & dragonflies
Hatch timeline · tomorrowPeak at 11 Uhr
12 Uhr(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 85%
Also:Autumn Olive52%Black Midge36%
Peak emergence window8 food groups active
Peak activity at 11 Uhr — 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.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 4 as a supporter.
Start free trial14-day free trial. Cancel anytime.
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
2
2
1
Grayling seasonSeason
1
2
2
2
2
1
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2
Large Brook DunHatch
2
3
2
Large StoneflyHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Hook 14–18 · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- Croatian fishing licence + local permit.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Sapnik z Medveje stene Terrain map
Water quality (WFD)
The full read · show the working · for Grayling · confidence 90%
How the 84 is built — score × weight = contribution
Temperature86 × 28%24.1
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time95 × 13%12.4
Pressure80 × 7%5.6
Insect activity76 × 12%9.1
Conditions total= 84
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via River Kolpaproxy
Prey activitymodelled from regional profilemodelled
Directions
Seasons & zones
- Trout 1 March → 30 September
- Grayling 16 May → 15 October
Kupica is a tributary of the Kupa system. Use the conservative Risnjak NP-aligned window (16 May – 15 October) until the specific concession confirms dates. Artificial fly or lure only.
- 16 May → 15 Oct · Artificial fly or artificial lure
Related guides
Booking & contacts
Kupica
Water temperature for Grayling
Ideal9°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 — conditions well-balanced, with time of day particularly in your favour.
Likely species
Caddisflies
Damselflies & dragonflies
Hatch timeline · tomorrowPeak at 11 Uhr
12 Uhr(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 85%
Also:Autumn Olive52%Black Midge36%
Peak emergence window8 food groups active
Peak activity at 11 Uhr — 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.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 4 as a supporter.
Start free trial14-day free trial. Cancel anytime.
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
2
2
1
Grayling seasonSeason
1
2
2
2
2
1
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2
Large Brook DunHatch
2
3
2
Large StoneflyHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Hook 14–18 · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- Croatian fishing licence + local permit.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Sapnik z Medveje stene Terrain map
Water quality (WFD)
- Ecology: Good
- Chemical: Unknown
WFD classification · HRCSRN0130_001
The full read · show the working · for Grayling · confidence 90%
How the 84 is built — score × weight = contribution
Temperature86 × 28%24.1
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time95 × 13%12.4
Pressure80 × 7%5.6
Insect activity76 × 12%9.1
Conditions total= 84
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via River Kolpaproxy
Prey activitymodelled from regional profilemodelled
Directions
Seasons & zones
- Trout 1 March → 30 September
- Grayling 16 May → 15 October
Kupica is a tributary of the Kupa system. Use the conservative Risnjak NP-aligned window (16 May – 15 October) until the specific concession confirms dates. Artificial fly or lure only.
- 16 May → 15 Oct · Artificial fly or artificial lure
Related guides
Booking & contacts