Rules at a glance
- Free fishing
- Fly only
Water temperature for Brown Trout
Ideal11°C est.ideal 10–16°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
Excellent — conditions well-balanced, with water temperature particularly in your favour.
Likely species
Stoneflies
Caddisflies
Caddisflies- CapererMost likelyLower confidence#10–12 · AdultBig autumn sedge; fish dry at last light.
- Net-spinning caddisAlso possibleLower confidenceNearest relative#12–14–16 · PupaWidespread riffle net-spinner; evening emergence.
- Large sedgesAlso possibleNearest relative#8–10 · AdultBig waked sedge in the last light and after dark.
- Green SedgeAlso possibleLower confidenceNearest relative#10–12–14–16 · NymphFree-living green caddis larva; fast stony riffles.
Gammarids
Hatch timeline · todayPeak at 18:00
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.
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Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 4 guilds as a supporter.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 as a supporter.
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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 · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
March BrownHatch
2
3
2
CapererHatch
2
3
3
2
Heather FlyHatch
2
2
Autumn DunHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Brown Trout
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
The full read · show the working · for Brown Trout · confidence 90%
How the 87 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity76 × 12%9.1
Conditions total= 86
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via River Dargle (Tinnehinch Fishery)proxy
Prey activitysurvey-backed invertebrate datasurvey
Directions
Seasons & zones
- Trout 1 March → 30 September
Related guides
Casting instructors near here
Booking & contacts
Derry Water
Water temperature for Brown Trout
Ideal11°C est.ideal 10–16°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
Excellent — conditions well-balanced, with water temperature particularly in your favour.
Likely species
Caddisflies
- CapererMost likelyLower confidence#10–12 · AdultBig autumn sedge; fish dry at last light.
- Net-spinning caddisAlso possibleLower confidenceNearest relative#12–14–16 · PupaWidespread riffle net-spinner; evening emergence.
- Large sedgesAlso possibleNearest relative#8–10 · AdultBig waked sedge in the last light and after dark.
- Green SedgeAlso possibleLower confidenceNearest relative#10–12–14–16 · NymphFree-living green caddis larva; fast stony riffles.
Hatch timeline · todayPeak at 18:00
Hatch predictions
Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
Top nymph shown — see all 4 guilds as a supporter.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey(1)
Hatch predictions
Top prey shown — see all 2 as a supporter.
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 · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
March BrownHatch
2
3
2
CapererHatch
2
3
3
2
Heather FlyHatch
2
2
Autumn DunHatch
2
3
2
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Fly box · Brown Trout
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
The full read · show the working · for Brown Trout · confidence 90%
How the 87 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity76 × 12%9.1
Conditions total= 86
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via River Dargle (Tinnehinch Fishery)proxy
Prey activitysurvey-backed invertebrate datasurvey
Directions
Seasons & zones
- Trout 1 March → 30 September
Related guides
Casting instructors near here
Booking & contacts