Lowland · Mixed · Co. Armagh / Lough Neagh Tributaries

River Blackwater (NI)

The River Blackwater flowing near Maghery, Northern Ireland, close to Lough Neagh

The Blackwater is a major Lough Neagh tributary flowing through Co.

Poor · Brown Trout
Partridge and Orange · 14-16
Poorlive now
Not the day for it
River temperature is the limiting factor today, not the flow. This is not the day to push it. Check the thermal advice above before you head out.
80% confidence
What moved it
  • Level0.81 mLast reading 8h ago
  • Water temp21.5°C
  • ClarityClear
Today's fly
Partridge and Orange
Partridge and Orange14-16
Upstream
Conditions on the water
Live gauge
Level
Steady
0.81 m
Last reading 8h ago
Water temp21.5°C
ClarityClear
Weather22°C
WindSW 15 km/h
Pressure1019 hPa
Rain · recent0.1 mm
Rain · ahead0.1 mm

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

Water temperature for Brown Trout
Warm — slow
22°C est.ideal 1016°C
0°14°28°
How to fish it · for Brown 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 21.5°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6pm

Hatch predictions

Today's headline hatch shown — see all 11 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 3 with Pro.

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Evidence
Survey-backed · regionalHigh confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Daddy Long LegsHatch
2
3
2
Terrestrial BeetlesHatch
2
3
3
2
Blue Winged OliveHatch
1
2
2
2
2
1
Black MidgeHatch
1
2
2
2
2
2
2
2
2
2
2
1

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

Ranked for today
Brown Trout fly box
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 2
Water here around 22°C — probably warm enough to stress Brown Trout . These are likely cooler.
Gallery · 2
  1. The River Blackwater flowing near Maghery, Northern Ireland, close to Lough Neagh
    River Blackwater at Maghery, Northern Ireland
  2. Terrain map of the venue
    Terrain map
About this water

The Blackwater is a major Lough Neagh tributary flowing through Co. Armagh — a slow, deep lowland river with excellent brown trout and dollaghan runs. The dollaghan run (July–October) is the main draw. Brown trout are plentiful throughout. The river also holds pike and some coarse fish. Managed by local clubs with day permits. The Blackwater responds slowly to rain — plan for sustained wet weather rather than single showers.

Hatches & food

No venue-specific hatch data yet; as a lowland main-stem river, expect a broad seasonal mix of upwings, sedges and midges typical of these slower Ulster rivers — a general expectation, not an observed hatch.

  • Mixed
The full read · show the working · for Brown Trout · confidence 80%
How the 18 is built — score × weight = contribution
Temperature10 × 28%2.8
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity63 × 12%7.6
Limiting factor: Water temperature (21.5°C) is outside Brown Trout's preferred range (10–16°C)= 58
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
  • Trout 1 March30 September
Related guides
Casting instructors near here
Booking & contacts