Rules at a glance
- Free fishing
- Fly only
Water temperature for White-spotted Char
Welfare risk22°C est.ideal 7–14°C
0°14°28°
How to fish it · for White-spotted Char
When
Late spring after the thaw, into autumn
Where
The Miomote falls out of the snow country of northern Niigata, a powerful river famed for the sea-run cherry salmon — sakuramasu — that climb it in spring,…
Why this works
Water at 21.7°C. This is the line where catch-and-release kills white-spotted char. Do not fish for them today.
Likely species
Mayflies
Mayflies- Iron BlueMost likely#16–18 · DunCold, grey day — the dun sits long. Good dry-fly water.
- Blue-winged oliveAlso possible#16–18 · DunDuns are up; a sherry spinner fall may follow.
- Large dark oliveAlso possible#14–16 · EmergerDead-drift the emerger — it's sitting in the film.
- Green drakeAlso possible#8–10 · DunDuns are up — the Spent Gnat spinners fall at dusk.
Caddisflies
Caddisflies- GrannomMost likely#14–16 · PupaPupa first, then dries as the adults come off.
- Satin sedgeAlso possible#12–14 · Egg-layingSkitter it at dusk — this one's fished, not dead-drifted.
Evidence
ModelledModerate confidence
Modelled from regional ecology — no survey or occurrence data for this water yet.
Updated 4 hours ago
Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Cicada (Semi)Hatch
2
2
Stenopsyche CaddisHatch
2
3
3
2
March BrownHatch
2
3
2
GrannomHatch
2
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
White-spotted Char fly box
12–14 · Sedge
Evening sedge — twitch or dead-drift it as the light goes.
10–12 · Terrestrial
Fish it tight to the bank on warm, breezy days.
Permits & access
Permit required — see local rules.
- Co-operative yugyoken required; sakuramasu are often specially regulated or restricted — verify before targeting
- Spawning closure in autumn.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
River in Niigata Prefecture. Terrain map
Conservation note
White-spotted char (iwana), yamame, and the sea-run cherry salmon sakuramasu (the migratory form of yamame); sakuramasu are conservation-sensitive and often restricted.
The full read · show the working · for White-spotted Char · confidence 90%
How the 0 is built — score × weight = contribution
Temperature0 × 28%0.0
Flow15 × 22%3.3
Clarity0 × 18%0.0
Feeding Time60 × 13%7.8
Pressure75 × 7%5.3
Insect activity50 × 12%6.0
Limiting factor: Water temperature (21.7°C) is outside White-spotted Char's preferred range (7–14°C)= 22
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Cooler water — back toward the 7–14 °C ideal band — would lift the score and ease welfare.
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
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
Booking & contacts
Miomote River
Water temperature for White-spotted Char
Welfare risk22°C est.ideal 7–14°C
0°14°28°
How to fish it · for White-spotted Char
When
Late spring after the thaw, into autumn
Where
The Miomote falls out of the snow country of northern Niigata, a powerful river famed for the sea-run cherry salmon — sakuramasu — that climb it in spring,…
Why this works
Water at 21.7°C. This is the line where catch-and-release kills white-spotted char. Do not fish for them today.
Likely species
Mayflies
- Iron BlueMost likely#16–18 · DunCold, grey day — the dun sits long. Good dry-fly water.
- Blue-winged oliveAlso possible#16–18 · DunDuns are up; a sherry spinner fall may follow.
- Large dark oliveAlso possible#14–16 · EmergerDead-drift the emerger — it's sitting in the film.
- Green drakeAlso possible#8–10 · DunDuns are up — the Spent Gnat spinners fall at dusk.
Caddisflies
- GrannomMost likely#14–16 · PupaPupa first, then dries as the adults come off.
- Satin sedgeAlso possible#12–14 · Egg-layingSkitter it at dusk — this one's fished, not dead-drifted.
Evidence
ModelledModerate confidence
Modelled from regional ecology — no survey or occurrence data for this water yet.
Updated 4 hours ago
Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Cicada (Semi)Hatch
2
2
Stenopsyche CaddisHatch
2
3
3
2
March BrownHatch
2
3
2
GrannomHatch
2
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
White-spotted Char fly box
12–14 · Sedge
Evening sedge — twitch or dead-drift it as the light goes.
10–12 · Terrestrial
Fish it tight to the bank on warm, breezy days.
Permits & access
Permit required — see local rules.
- Co-operative yugyoken required; sakuramasu are often specially regulated or restricted — verify before targeting
- Spawning closure in autumn.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
River in Niigata Prefecture. Terrain map
Conservation note
White-spotted char (iwana), yamame, and the sea-run cherry salmon sakuramasu (the migratory form of yamame); sakuramasu are conservation-sensitive and often restricted.
The full read · show the working · for White-spotted Char · confidence 90%
How the 0 is built — score × weight = contribution
Temperature0 × 28%0.0
Flow15 × 22%3.3
Clarity0 × 18%0.0
Feeding Time60 × 13%7.8
Pressure75 × 7%5.3
Insect activity50 × 12%6.0
Limiting factor: Water temperature (21.7°C) is outside White-spotted Char's preferred range (7–14°C)= 22
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Cooler water — back toward the 7–14 °C ideal band — would lift the score and ease welfare.
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
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
Booking & contacts