Rules at a glance
- Free fishing
- Fly only
- Barbless
Water temperature for Grayling
Ideal14°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 right today, though insect activity could be better. Grayling is active in the cooler margins of the season.
Likely species
Mayflies
Mayflies- Anglers curse mayfliesMost likelyLower confidenceNearest relative#20–22 · SpinnerGo tiny: 20-22 spent spinner, single fly, long tippet.
- Turkey BrownAlso possibleLower confidence#14–16 · DunSmall spring dun on slower glides and margins.
- Late March BrownAlso possibleLower confidence#12–14 · DunLate-season upland riffle dun, dusk emergence.
- Iron BlueAlso possibleNearest relative#16–18 · DunCold, grey day — the dun sits long. Good dry-fly water.
Caddisflies
Caddisflies- Green SedgeMost likelyLower confidenceNearest relative#10–12–14–16 · NymphFree-living green caddis larva; fast stony riffles.
- Stone-case caddisAlso possibleLower confidenceNearest relative#14–16–18 · NymphTiny stone-cased larva; clean gravel riffles.
- GrannomAlso possibleNearest relative#14–16 · PupaPupa first, then dries as the adults come off.
- Net-spinning caddis (S. Europe)Also possibleLower confidenceNearest relative#12–14–16 · PupaWidespread riffle net-spinner; evening emergence.
Stoneflies
Stoneflies- Little Brown StoneMost likelyLower confidence#16–18 · AdultSmall dark stone nymph or adult in early spring.
- NeedleflyAlso possibleLower confidenceNearest relative#16–18 · AdultSmall slender stonefly; clean, cold headwater riffles.
Hatch timeline · todayPeak at 13:00
12:00(now) — Reed Smut
Stage: On emergersApproach: Emerger or dryActivity: 81%
Also:Pale Watery77%Cinnamon Sedge52%
Peak emergence window9 food groups active
Peak activity at 13:00 — Pale Watery (Pale Watery, Degree-days at peak)
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 2 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
2
1
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Permits & access
Permit required — see local rules.
- RD Idrija
- Fly-only, barbless.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
- Idrijca6.0 kmBrown trout · Marble trout · Grayling
- Cerknica (Idrijca tributary)10 kmMarble trout · Marble brown hybrid trout · Brown trout80
- River Trebuščica16 kmBrown trout · Marble trout
- Hubelj18 kmMarble trout · Marble brown hybrid trout · Brown trout
- Poljanska Sora18 kmGrayling · Brown trout · Rainbow trout
Gallery · 1
Terrain map
The full read · show the working · for Grayling · confidence 90%
How the 86 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity55 × 12%6.6
Conditions total= 81
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Idrijcaproxy
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 1 March → 30 September
- Grayling 16 May → 30 November
Slovenian common default: grayling 16 May – 30 November (lipan). Permit and fishing district controlled — dates may vary by specific water. Always check the Ribiška Družina (fishing district) permit for the specific beat.
Prime sport 1 September → 30 November
- Marble trout 1 April → 31 October
Related guides
Booking & contacts
Kanomljica
Water temperature for Grayling
Ideal14°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 right today, though insect activity could be better. Grayling is active in the cooler margins of the season.
Likely species
Mayflies
- Anglers curse mayfliesMost likelyLower confidenceNearest relative#20–22 · SpinnerGo tiny: 20-22 spent spinner, single fly, long tippet.
- Turkey BrownAlso possibleLower confidence#14–16 · DunSmall spring dun on slower glides and margins.
- Late March BrownAlso possibleLower confidence#12–14 · DunLate-season upland riffle dun, dusk emergence.
- Iron BlueAlso possibleNearest relative#16–18 · DunCold, grey day — the dun sits long. Good dry-fly water.
Caddisflies
- Green SedgeMost likelyLower confidenceNearest relative#10–12–14–16 · NymphFree-living green caddis larva; fast stony riffles.
- Stone-case caddisAlso possibleLower confidenceNearest relative#14–16–18 · NymphTiny stone-cased larva; clean gravel riffles.
- GrannomAlso possibleNearest relative#14–16 · PupaPupa first, then dries as the adults come off.
- Net-spinning caddis (S. Europe)Also possibleLower confidenceNearest relative#12–14–16 · PupaWidespread riffle net-spinner; evening emergence.
Stoneflies
- Little Brown StoneMost likelyLower confidence#16–18 · AdultSmall dark stone nymph or adult in early spring.
- NeedleflyAlso possibleLower confidenceNearest relative#16–18 · AdultSmall slender stonefly; clean, cold headwater riffles.
Hatch timeline · todayPeak at 13:00
12:00(now) — Reed Smut
Stage: On emergersApproach: Emerger or dryActivity: 81%
Also:Pale Watery77%Cinnamon Sedge52%
Peak emergence window9 food groups active
Peak activity at 13:00 — Pale Watery (Pale Watery, Degree-days at peak)
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 2 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
2
1
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Grayling
Permits & access
Permit required — see local rules.
- RD Idrija
- Fly-only, barbless.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 1
Terrain map
The full read · show the working · for Grayling · confidence 90%
How the 86 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity55 × 12%6.6
Conditions total= 81
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Idrijcaproxy
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 1 March → 30 September
- Grayling 16 May → 30 November
Slovenian common default: grayling 16 May – 30 November (lipan). Permit and fishing district controlled — dates may vary by specific water. Always check the Ribiška Družina (fishing district) permit for the specific beat.
Prime sport 1 September → 30 November
- Marble trout 1 April → 31 October
Related guides
Booking & contacts