Rules at a glance
- Licence required
- Fly only
Water temperature for Grayling
Ideal10°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
June through the last Sunday of September, when the closed season for temolo lifts. Only one grayling per angler may be retained per year, so treat this as an incidental fish rather than a target.
Where
Faster gravel runs and riffle heads in the more stable middle reaches, away from the most actively shifting braids.
Method
Euro-nymph the faster water; small dries when naturals show on calmer afternoons.
Kit
10 ft #3 nymphing rod, 4 to 5 lb fluoro; 9 ft #4 for dries. 12 ft leader.
Likely species
Mayflies
Mayflies- Angler's CurseMost likelyLower 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.
- 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.
Stoneflies
Caddisflies
Caddisflies- Green SedgeMost likelyLower 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.
- Saddle-case CaddisAlso possibleLower confidenceNearest relative#16–18 · AdultTiny blackish caddis; fast riffles, early summer.
Aquatic beetles
Aquatic beetles- Diving beetlesMost likelyLower confidence#8–10–12 · AdultTwitch a beetle pattern along weedy edges at dusk.
Gammarids
Oligochaetes
- Aquatic wormsMost likelyLower confidence#12–14–16 · AdultDead-drift a worm pattern deep - a year-round staple.
Hatch timeline · tomorrowPeak at 11h
12h(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 95%
Also:Autumn Olive63%Black Midge37%
Peak emergence windowWeather boost7 food groups active
Peak activity at 11h — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)
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
Supporters see what else is on the menu.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Alpine RhithrogenaHatch
2
3
3
2
Sculpin / Baitfish (Rivers)Hatch
2
3
3
3
3
3
3
3
2
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2
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.
- ETPI (Ente Tutela Patrimonio Ittico) regional licence required — course-based, roughly €46 for residents
- FVG Zone B season (2026 Calendario Pesca Sportiva): trout open 07:00 on 29 March to 27 September, with a catch-and-release-only extension to 31 October
- Marble trout minimum size 35cm on this reach (Collegi 9/10), one fish a day
- Grayling minimum size 60cm, and FVG limits every angler to ONE retained grayling per calendar year across the whole region
- Single barbless hook mandatory on No-Kill and RPS water.
What's coming
Plan ahead
5-day outlook
Fishing better nearby · 5
Gallery · 2
Terrain map
The full read · show the working · for Grayling · confidence 90%
How the 0 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time90 × 13%11.7
Pressure80 × 7%5.6
Insect activity69 × 12%8.3
Conditions total= 87
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
Directions
Seasons & zones
- Trout 2026-03-29 → 2026-09-27
- Grayling 2026-06-01 → 2026-09-27
Rules are set at province or association level — check locally.
- Marble trout 2026-03-29 → 2026-09-27
Related guides
Booking & contacts
Tagliamento
Water temperature for Grayling
Ideal10°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
June through the last Sunday of September, when the closed season for temolo lifts. Only one grayling per angler may be retained per year, so treat this as an incidental fish rather than a target.
Where
Faster gravel runs and riffle heads in the more stable middle reaches, away from the most actively shifting braids.
Method
Euro-nymph the faster water; small dries when naturals show on calmer afternoons.
Kit
10 ft #3 nymphing rod, 4 to 5 lb fluoro; 9 ft #4 for dries. 12 ft leader.
Likely species
Mayflies
- Angler's CurseMost likelyLower 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.
- 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.
Caddisflies
- Green SedgeMost likelyLower 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.
- Saddle-case CaddisAlso possibleLower confidenceNearest relative#16–18 · AdultTiny blackish caddis; fast riffles, early summer.
Aquatic beetles
- Diving beetlesMost likelyLower confidence#8–10–12 · AdultTwitch a beetle pattern along weedy edges at dusk.
Oligochaetes
- Aquatic wormsMost likelyLower confidence#12–14–16 · AdultDead-drift a worm pattern deep - a year-round staple.
Hatch timeline · tomorrowPeak at 11h
12h(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 95%
Also:Autumn Olive63%Black Midge37%
Peak emergence windowWeather boost7 food groups active
Peak activity at 11h — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)
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
Supporters see what else is on the menu.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Alpine RhithrogenaHatch
2
3
3
2
Sculpin / Baitfish (Rivers)Hatch
2
3
3
3
3
3
3
3
2
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2
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.
- ETPI (Ente Tutela Patrimonio Ittico) regional licence required — course-based, roughly €46 for residents
- FVG Zone B season (2026 Calendario Pesca Sportiva): trout open 07:00 on 29 March to 27 September, with a catch-and-release-only extension to 31 October
- Marble trout minimum size 35cm on this reach (Collegi 9/10), one fish a day
- Grayling minimum size 60cm, and FVG limits every angler to ONE retained grayling per calendar year across the whole region
- Single barbless hook mandatory on No-Kill and RPS water.
What's coming
Plan ahead
5-day outlook
Fishing better nearby · 5
Gallery · 2
Terrain map
The full read · show the working · for Grayling · confidence 90%
How the 0 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time90 × 13%11.7
Pressure80 × 7%5.6
Insect activity69 × 12%8.3
Conditions total= 87
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
Directions
Seasons & zones
- Trout 2026-03-29 → 2026-09-27
- Grayling 2026-06-01 → 2026-09-27
Rules are set at province or association level — check locally.
- Marble trout 2026-03-29 → 2026-09-27
Related guides
Booking & contacts