Rules at a glance
- Free fishing
- Fly only
Water temperature for Brown Trout
Ideal15°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the FVG trout season. The Natisone runs gin-clear for a limestone river, so approach and light matter more here than almost anywhere else in the region.
Where
Pool tails and current seams through the gorges below Pulfero and San Pietro al Natisone, where the valley narrows.
Method
Long, fine leaders and careful wading — the clarity that makes this river beautiful also makes it easy to put fish down. Upstream nymph and dry-dropper both work if you stay unseen.
Kit
9 to 10 ft #4, floating line, 12 ft leader to 4 to 5 lb fluoro, fined down further in low water.
Why this works
Excellent — conditions well-balanced, with water temperature particularly in your favour.
Likely species
Mayflies
Mayflies- Anglers curse mayfliesMost 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.
- Ephemera vulgata (lake mayfly)Also possibleLower confidenceNearest relative#8–10–12 · NymphLarge lake/slow-river mayfly; burrows soft sediment.
Caddisflies
Caddisflies- GrannomMost likelyNearest 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.
- CapererAlso possibleLower confidence#10–12 · AdultBig autumn sedge; fish dry at last light.
- Satin sedgeAlso possibleLower confidence#12–14 · Egg-layingSkitter it at dusk — this one's fished, not dead-drifted.
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 13h
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.
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Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 3 guilds as a supporter.
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Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 3 as a supporter.
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Evidence
Survey-backed · regionalModerate confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · September 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 · Brown Trout
18-22 · Pattern
Upstream dry, in the film
Permits & access
Permit required — see local rules.
- ETPI regional licence required
- FVG Zone B season: trout open 07:00 on 29 March to 27 September, catch-and-release extension to 31 October
- Marble trout minimum size follows the FVG regional default of 50cm in this collegio (Collegio 13 Cividale) — no local 35cm exception found for the Natisone
- Grayling minimum size 60cm, one retained specimen per angler per calendar year region-wide
- Single barbless hook mandatory on the Cividale No-Kill and RPS water.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Terrain map
The full read · show the working · for Brown Trout · confidence 90%
How the 86 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time75 × 13%9.8
Pressure80 × 7%5.6
Insect activity70 × 12%8.4
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
Natisone
Water temperature for Brown Trout
Ideal15°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the FVG trout season. The Natisone runs gin-clear for a limestone river, so approach and light matter more here than almost anywhere else in the region.
Where
Pool tails and current seams through the gorges below Pulfero and San Pietro al Natisone, where the valley narrows.
Method
Long, fine leaders and careful wading — the clarity that makes this river beautiful also makes it easy to put fish down. Upstream nymph and dry-dropper both work if you stay unseen.
Kit
9 to 10 ft #4, floating line, 12 ft leader to 4 to 5 lb fluoro, fined down further in low water.
Why this works
Excellent — conditions well-balanced, with water temperature particularly in your favour.
Likely species
Mayflies
- Anglers curse mayfliesMost 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.
- Ephemera vulgata (lake mayfly)Also possibleLower confidenceNearest relative#8–10–12 · NymphLarge lake/slow-river mayfly; burrows soft sediment.
Caddisflies
- GrannomMost likelyNearest 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.
- CapererAlso possibleLower confidence#10–12 · AdultBig autumn sedge; fish dry at last light.
- Satin sedgeAlso possibleLower confidence#12–14 · Egg-layingSkitter it at dusk — this one's fished, not dead-drifted.
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 13h
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 3 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 3 as a supporter.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalModerate confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · September 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 · Brown Trout
18-22 · Pattern
Upstream dry, in the film
Permits & access
Permit required — see local rules.
- ETPI regional licence required
- FVG Zone B season: trout open 07:00 on 29 March to 27 September, catch-and-release extension to 31 October
- Marble trout minimum size follows the FVG regional default of 50cm in this collegio (Collegio 13 Cividale) — no local 35cm exception found for the Natisone
- Grayling minimum size 60cm, one retained specimen per angler per calendar year region-wide
- Single barbless hook mandatory on the Cividale No-Kill and RPS water.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Terrain map
The full read · show the working · for Brown Trout · confidence 90%
How the 86 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time75 × 13%9.8
Pressure80 × 7%5.6
Insect activity70 × 12%8.4
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