Freestone · Sedimentary · Honshū

Tama River (upper / Okutama)

Tama River, Mitake Valley
Poor · Rainbow Trout
Cicada (foam semi pattern) · 6-10
Poorlive now
Not the day for it
Low and clear — careful approach country. A morning for the obvious fish only.
90% confidence
What moved it
  • LevelLight rain recentlyNo gauge reading
  • Water temp22.7°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 temp22.7°C
ClarityClear
Weather27°C
WindNW 7 km/h
Pressure1005 hPa
Rain · recent6.2 mm
Rain · ahead15.2 mm

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

Water temperature for Rainbow Trout
Warm — slow
23°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
Water at 22.7°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Likely species
Mayflies
  • Iron BlueMost likely
    #16–18 · Dun
    Cold, grey day — the dun sits long. Good dry-fly water.
  • Blue-winged oliveAlso possible
    #16–18 · Dun
    Duns are up; a sherry spinner fall may follow.
  • Green drakeAlso possible
    #8–10 · Dun
    Duns are up — the Spent Gnat spinners fall at dusk.
  • Large dark oliveAlso possible
    #14–16 · Emerger
    Dead-drift the emerger — it's sitting in the film.
Caddisflies
  • GrannomMost likely
    #14–16 · Pupa
    Pupa first, then dries as the adults come off.
  • Satin sedgeAlso possible
    #12–14 · Egg-laying
    Skitter it at dusk — this one's fished, not dead-drifted.
Hatch timeline · todayPeak at 6am

Hatch predictions

Today's headline hatch shown — see all 4 active hatches hour by hour with Pro.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 3 with Pro.

Start free trial

14-day free trial. Cancel anytime.

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Stenopsyche CaddisHatch
2
3
3
2
Cicada (Semi)Hatch
2
2
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2

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.
  • Local co-operative yugyoken required (day/annual ticket); managed stocked reaches with method rules
  • Confirm before fishing.
What's coming
Plan ahead
5-day outlook
Water here around 23°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. Tama River, Mitake Valley
    Upper Tama at Mitake Valley
  2. Terrain map of the venue
    Terrain map
Conservation note

Stocked rainbow with wild white-spotted char (iwana) and yamame.

The full read · show the working · for Rainbow Trout · confidence 90%
How the 10 is built — score × weight = contribution
Temperature5 × 28%1.4
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time55 × 13%7.2
Pressure75 × 7%5.3
Insect activity69 × 12%8.3
Limiting factor: Water temperature (22.7°C) is outside Rainbow Trout's preferred range (10–18°C)= 55
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
What would change the calculation
Cooler water — back toward the 10–18 °C ideal band — would lift the score and ease welfare.
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