Tailwater · Mixed · New Hampshire, US

Androscoggin River — Errol

Kayaks on the upper reaches of the Androscoggin River, just below the bridge at Errol
Prime · Brook Trout
Blue Winged Olive · 18-22
Primelive now
About as good as it gets
River steady at a fishable height. On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
90% confidence
What moved it
  • Level0.55 mLast reading 3h ago
  • Water temp13.7°C
  • ClarityClear
Today's fly
Blue Winged Olive
Blue Winged Olive18-22
Proven pattern for this period
Conditions on the water
Live gauge
Level
Steady
0.55 m
Last reading 3h ago
Water temp13.7°C
ClarityClear
Weather2°C
WindNW 23 km/h
Pressure1017 hPa
Rain · recent11.3 mm
Rain · ahead0.0 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Brook Trout
Ideal
14°C est.ideal 10–16°C
0°14°28°

A dam sets this river's temperature, not the weather, so it can shift several degrees within hours when the release changes. It also warms as it runs away from the dam.

How to fish it · for Brook 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.
Likely species
Mayflies
Chironomids
Damselflies & dragonflies
Gammarids
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 6 active hatches hour by hour as a supporter.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Supporters see the full sub-surface read.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 as a supporter.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

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
2
2
2
2
2
2
2
1
SulphurHatch
2
3
2
Trico (Eastern)Hatch
2
3
3
2
Eastern Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Eastern Summer BWO (Drunella)Hatch
2
3
3
2

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

Ranked for today
Fly box · Brook Trout
Permits & access
Permit required — see local rules.
  • NH Androscoggin below Errol Dam — verify exact reach open-water dates, tackle and bag/length rules against NH Fish & Game
  • Dam-influenced flow
  • CONSERVATION: native brook trout are heat-sensitive — careful handling and summer thermal restraint.
What's coming
Plan ahead
5-day outlook
Other water nearby · 3
Rapid River / Rangeley region
16 km
0
Brook trout
Magalloway River
19 km
0
Brook trout
Connecticut Lakes / Upper Connecticut River
36 km
0
Brook trout · Rainbow trout · Brown trout
Gallery · 2
  1. Kayaks on the upper reaches of the Androscoggin River, just below the bridge at Errol
    The Androscoggin River near Errol, New Hampshire, lined with autumn foliage.
  2. Terrain map of the venue
    Terrain map
Water quality · US Clean Water Act
  • Aquatic life: Not assessed
  • Fish consumption: Impaired
What this classification means

Fish consumption: Consumption advisory (Mercury) — fish for sport, not the table.

EPA ATTAINS assessment unit 'ANDROSCOGGIN RIVER' (NHRIV400010602-04), 2024 Integrated Report. Aquatic Life use: Insufficient Information. Listed impairment causes: Mercury. This is a Clean Water Act assessment-unit classification (the US analogue of WFD), not a live reading.

Status is for the Clean Water Act assessment unit covering this reach.

EPA ATTAINS (Clean Water Act) · NHRIV400010602-04

The full read · show the working · for Brook Trout · confidence 90%
How the 84 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure75 × 7%5.3
Insect activity72 × 12%8.6
Conditions total= 84
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
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Booking & contacts