Mountain Freestone · Volcanic · Honshū

Azusa River (Kamikōchi)

Japan Alps river
Prime · Rainbow Trout
Cicada (foam semi pattern) · 6-10
Primelive now
About as good as it gets
Low and clear — careful approach country. Take your time — read the water before you cast.
90% confidence
What moved it
  • LevelLight rain recentlyNo gauge reading
  • Water temp17.3°C
  • ClarityClear
Today's fly
CI
Cicada (foam semi pattern)6-10
High-confidence seasonal pick
Conditions on the water
Estimate
Level
Light rain recently
No gauge reading
Water temp17.3°C
ClarityClear
Weather15°C
WindN 3 km/h
Pressure1019 hPa
Rain · recent9.0 mm
Rain · ahead25.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for Rainbow Trout
Ideal
17°C est.ideal 10–18°C
0°14°28°
How to fish it · for Rainbow 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 time of day could be better.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 9 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 2 with Pro.

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Evidence
ModelledModerate confidence

Modelled from regional ecology — no survey or occurrence data for this water yet.

Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Rainbow Trout fly box
Permits & access
Permit required — see local rules.
  • Kamikōchi is protected; local co-operative rules and a yugyoken apply, with access and method limits
  • Confirm before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 2
Kurobe River (upper gorge)
33 km
White spotted char
Kiso River (upper / Kiso Valley)
50 km
15
White spotted char · Amago · Rainbow trout
Gallery · 2
  1. Japan Alps river
    Alpine river through UNESCO-protected Kamikōchi.
  2. Terrain map of the venue
    Terrain map
Conservation note

White-spotted char (iwana), yamame, and stocked rainbow. Iwana and yamame are the wild natives.

The full read · show the working · for Rainbow Trout · confidence 90%
How the 80 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time55 × 13%7.2
Pressure75 × 7%5.3
Insect activity57 × 12%6.8
Conditions total= 80
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Char late February to April → late September to mid-October

    Honshu/Shikoku/Kyushu keiryu are managed by local fishery co-operatives — a yugyoken (day/annual ticket) is required, and most streams close around 30 September / mid-October for spawning. Species are surfaced in prose only (no engine slugs for yamame, amago or iwana). Legal status: guidance_not_permission.

Related guides
Euro Nymphingsubsurface methods
Booking & contacts