Rules at a glance
- Free fishing
- Fly only
- Barbless
Water temperature for Chub
Ideal16°C est.ideal 14–22°C
0°14°28°
How to fish it · for Chub
When
April–October
Where
Not to be confused with the Idrijca — this is the Idrija, known on the Italian side of the border as the Judrio, a border river through the Goriška Brda wine…
Why this works
Good — water temperature is working for you, but time of day is the limiting factor today.
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.
- Ephemera vulgata (lake mayfly)Also possibleLower confidenceNearest relative#8–10–12 · NymphLarge lake/slow-river mayfly; burrows soft sediment.
- Turkey BrownAlso possibleLower confidence#14–16 · DunSmall spring dun on slower glides and margins.
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.
- 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.
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 18 Uhr
12 Uhr(now) — Reed Smut
Stage: On emergersApproach: Emerger or dryActivity: 86%
Also:Pale Watery68%Flying Ants57%Cinnamon Sedge55%
Peak emergence window10 food groups active
Peak activity at 18 Uhr — Evening Sedge (Evening 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 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
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 · Chub
Hook 8–10 weighted · Fly
in season · matches water height · all-rounder
Permits & access
Permit required — see local rules.
- Fly-only, barbless.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Fiume Judrio, alto corso Terrain map
The full read · show the working · for Chub · confidence 65%
Perfect · warmwater comfort — temperature and clarity led
Water temperatureWater temp 14°C — prime band for chub.
FlowStable flow — predictable holding lies.
SeasonPrime month for this species.
Water clarityWater clarity clear — read accordingly for chub.
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
Directions
Seasons & zones
- Trout 1 March → 30 September
- Marble trout 1 April → 31 October
Related guides
Booking & contacts
Idrija (Judrio)
Water temperature for Chub
Ideal16°C est.ideal 14–22°C
0°14°28°
How to fish it · for Chub
When
April–October
Where
Not to be confused with the Idrijca — this is the Idrija, known on the Italian side of the border as the Judrio, a border river through the Goriška Brda wine…
Why this works
Good — water temperature is working for you, but time of day is the limiting factor today.
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.
- Ephemera vulgata (lake mayfly)Also possibleLower confidenceNearest relative#8–10–12 · NymphLarge lake/slow-river mayfly; burrows soft sediment.
- Turkey BrownAlso possibleLower confidence#14–16 · DunSmall spring dun on slower glides and margins.
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.
- 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.
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 18 Uhr
12 Uhr(now) — Reed Smut
Stage: On emergersApproach: Emerger or dryActivity: 86%
Also:Pale Watery68%Flying Ants57%Cinnamon Sedge55%
Peak emergence window10 food groups active
Peak activity at 18 Uhr — Evening Sedge (Evening 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 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
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 · Chub
Hook 8–10 weighted · Fly
in season · matches water height · all-rounder
Permits & access
Permit required — see local rules.
- Fly-only, barbless.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Fiume Judrio, alto corso Terrain map
The full read · show the working · for Chub · confidence 65%
Perfect · warmwater comfort — temperature and clarity led
Water temperatureWater temp 14°C — prime band for chub.
FlowStable flow — predictable holding lies.
SeasonPrime month for this species.
Water clarityWater clarity clear — read accordingly for chub.
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
Directions
Seasons & zones
- Trout 1 March → 30 September
- Marble trout 1 April → 31 October
Related guides
Booking & contacts