Stoneflies
Gammarids
The Iijoki is northern Finland's major trout and grayling river. Excellent for drift fishing and dry-fly tactics in summer. Productive system with strong fish populations.
- Granite
Rules at a glance
- Fly only
Water temperature for Grayling
Ideal6°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Midday window — grayling feed best from late morning into early afternoon.
Where
Work runs and glides — grayling shoal in the bottom third of the water column.
Method
Tight-line nymph the bottom third with weighted patterns.
Kit
10 ft #3 rod, floating line, long leader to 4 lb fluoro for nymphs.
Why this works
Excellent — water temperature is working for you, but time of day is the limiting factor today. Grayling feeds actively in cold water — peak winter sport.
Likely species
Hatch timeline · todayPeak at 11am
12pm(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 40%
Also:Black Midge38%Autumn Olive23%
Peak emergence window3 food groups active
Peak activity at 11am — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)
Sub-surface · on the nymphunder the surface
Hatch predictions
Supporters see the full sub-surface read.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
1
Grayling seasonSeason
2
2
1
1
2
2
2
2
2
2
Nordic SpringflyHatch
2
3
3
2
Ladoga CaddisHatch
2
3
2
Arctic Cased CaddisHatch
2
3
3
3
2
Large Summer DunHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Grayling fly box
Hook 14–18 · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- Calendar permit + river permit via eraluvat.fi.
What's coming
Plan ahead
5-day outlook
Gallery · 2
Iijoki Finland Terrain map
About this water
The full read · show the working · for Grayling · confidence 50%
How the 86 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time10 × 13%1.3
Pressure80 × 7%5.6
Insect activity25 × 12%3.0
Conditions total= 71
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 1 May → 30 September
- Grayling 1 June → 31 March
Finnish inland grayling (harjus) rule south of 67°N: closed 1 April – 31 May. Open 1 June – 31 March. Grayling is fully protected in sea areas. Minimum size typically 30-35 cm depending on water. Check Metsähallitus (state waters) or local fishing association permit.
Closed in spring for spawning.
Prime sport 1 August → 30 November
Related guides
Booking & contacts
Iijoki
The Iijoki is northern Finland's major trout and grayling river.
Water temperature for Grayling
Ideal6°C est.ideal 4–14°C
0°14°28°
How to fish it · for Grayling
When
Midday window — grayling feed best from late morning into early afternoon.
Where
Work runs and glides — grayling shoal in the bottom third of the water column.
Method
Tight-line nymph the bottom third with weighted patterns.
Kit
10 ft #3 rod, floating line, long leader to 4 lb fluoro for nymphs.
Why this works
Excellent — water temperature is working for you, but time of day is the limiting factor today. Grayling feeds actively in cold water — peak winter sport.
Likely species
Hatch timeline · todayPeak at 11am
12pm(now) — Autumn Needle Fly
Stage: Creeping nymphsApproach: Heavy nymphActivity: 40%
Also:Black Midge38%Autumn Olive23%
Peak emergence window3 food groups active
Peak activity at 11am — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)
Sub-surface · on the nymphunder the surface
Hatch predictions
Supporters see the full sub-surface read.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalHigh confidence
Backed by regional invertebrate surveys; no sampling on this exact reach yet.
Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
1
Grayling seasonSeason
2
2
1
1
2
2
2
2
2
2
Nordic SpringflyHatch
2
3
3
2
Ladoga CaddisHatch
2
3
2
Arctic Cased CaddisHatch
2
3
3
3
2
Large Summer DunHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Grayling fly box
Hook 14–18 · Fly
in season · matches water height
Permits & access
Permit required — see local rules.
- Calendar permit + river permit via eraluvat.fi.
What's coming
Plan ahead
5-day outlook
Gallery · 2
Iijoki Finland Terrain map
About this water
The Iijoki is northern Finland's major trout and grayling river. Excellent for drift fishing and dry-fly tactics in summer. Productive system with strong fish populations.
- Granite
The full read · show the working · for Grayling · confidence 50%
How the 86 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time10 × 13%1.3
Pressure80 × 7%5.6
Insect activity25 × 12%3.0
Conditions total= 71
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
- Trout 1 May → 30 September
- Grayling 1 June → 31 March
Finnish inland grayling (harjus) rule south of 67°N: closed 1 April – 31 May. Open 1 June – 31 March. Grayling is fully protected in sea areas. Minimum size typically 30-35 cm depending on water. Check Metsähallitus (state waters) or local fishing association permit.
Closed in spring for spawning.
Prime sport 1 August → 30 November
Related guides
Booking & contacts