Rules at a glance
- Free fishing
- Fly only
Water temperature for Brown Trout
Ideal11°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
Excellent — water temperature is right today, though insect activity could be better.
Likely species
Mayflies
Mayflies- Blue-winged oliveMost likely#16–18 · DunDuns are up; a sherry spinner fall may follow.
- Anglers curse mayfliesAlso possibleLower confidenceNearest relative#20–22 · SpinnerGo tiny: 20-22 spent spinner, single fly, long tippet.
- Large dark oliveAlso possible#14–16 · EmergerDead-drift the emerger — it's sitting in the film.
- Ephemera vulgata (lake mayfly)Also possibleLower confidenceNearest relative#8–10–12 · NymphLarge lake/slow-river mayfly; burrows soft sediment.
Caddisflies
Caddisflies- CapererMost likelyLower confidence#10–12 · AdultBig autumn sedge; fish dry at last light.
- Saddle-case CaddisAlso possibleLower confidenceNearest relative#16–18 · AdultTiny blackish caddis; fast riffles, early summer.
- Green SedgeAlso possibleLower confidenceNearest relative#10–12–14–16 · NymphFree-living green caddis larva; fast stony riffles.
- GrannomAlso possibleNearest relative#14–16 · PupaPupa first, then dries as the adults come off.
Damselflies & dragonflies
Damselflies & dragonflies- Migrant HawkerMost likelyLower confidence#6–8 · NymphStrip a big hawker nymph erratically near cover.
- DamselfliesAlso possibleNearest relative#10–12 · NymphSlow-retrieve a damsel nymph along the weed edges.
Hatch timeline · todayPeak at 18h
12h(now) — Black Midge
Stage: On emergersApproach: Emerger or dryActivity: 57%
Also:Autumn Needle Fly38%Iron Blue35%Brown Sedge29%
Peak emergence window8 food groups active
Peak activity at 18h — Large Cinnamon Sedge (Large Cinnamon Sedge, Weather boost)
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.
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
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
Fly box · Brown Trout
Top
6-10 · Pattern
High-confidence seasonal pick
Permits & access
Permit required — see local rules.
- Bela Krajina ribiška družina (likely RD Črnomelj) — not independently confirmed.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Krupa river in winter Terrain map
The full read · show the working · for Brown Trout · confidence 90%
How the 80 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 80
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
Directions
Seasons & zones
- Trout 1 March → 30 September
Related guides
Booking & contacts
Krupa
Water temperature for Brown Trout
Ideal11°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
Excellent — water temperature is right today, though insect activity could be better.
Likely species
Mayflies
- Blue-winged oliveMost likely#16–18 · DunDuns are up; a sherry spinner fall may follow.
- Anglers curse mayfliesAlso possibleLower confidenceNearest relative#20–22 · SpinnerGo tiny: 20-22 spent spinner, single fly, long tippet.
- Large dark oliveAlso possible#14–16 · EmergerDead-drift the emerger — it's sitting in the film.
- Ephemera vulgata (lake mayfly)Also possibleLower confidenceNearest relative#8–10–12 · NymphLarge lake/slow-river mayfly; burrows soft sediment.
Caddisflies
- CapererMost likelyLower confidence#10–12 · AdultBig autumn sedge; fish dry at last light.
- Saddle-case CaddisAlso possibleLower confidenceNearest relative#16–18 · AdultTiny blackish caddis; fast riffles, early summer.
- Green SedgeAlso possibleLower confidenceNearest relative#10–12–14–16 · NymphFree-living green caddis larva; fast stony riffles.
- GrannomAlso possibleNearest relative#14–16 · PupaPupa first, then dries as the adults come off.
Damselflies & dragonflies
- Migrant HawkerMost likelyLower confidence#6–8 · NymphStrip a big hawker nymph erratically near cover.
- DamselfliesAlso possibleNearest relative#10–12 · NymphSlow-retrieve a damsel nymph along the weed edges.
Hatch timeline · todayPeak at 18h
12h(now) — Black Midge
Stage: On emergersApproach: Emerger or dryActivity: 57%
Also:Autumn Needle Fly38%Iron Blue35%Brown Sedge29%
Peak emergence window8 food groups active
Peak activity at 18h — Large Cinnamon Sedge (Large Cinnamon Sedge, Weather boost)
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.
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
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
Fly box · Brown Trout
Top
6-10 · Pattern
High-confidence seasonal pick
Permits & access
Permit required — see local rules.
- Bela Krajina ribiška družina (likely RD Črnomelj) — not independently confirmed.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Krupa river in winter Terrain map
The full read · show the working · for Brown Trout · confidence 90%
How the 80 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 80
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
Directions
Seasons & zones
- Trout 1 March → 30 September
Related guides
Booking & contacts