Upper Mondego rising in the Serra da Estrela flows through mountain water with wild brown trout. The upper basin above Nelas has the best fly fishing. Spring and early summer are the working months before heat arrives.
- Granite
Rules at a glance
- Public water
- Licence required
Water temperature for Brown Trout
Warm — slow22°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
Water at 22°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 2 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 2 with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalModerate 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
1
Large Dark OliveHatch
1
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Autumn OliveHatch
1
2
1
GrannomHatch
1
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Brown Trout fly box
A wild brown trout pack for northern and mountain Portugal. River-first, compact, and practical, with nymphs leading and dry flies taking over in the stronger windows.
14-18 · Pattern
Upstream dry, on top
6-10 · Pattern
Swing, sub-surface
Permits & access
Permit required — see local rules.
- Licença de Pesca Desportiva (Portuguese fishing license)
- Regional variation; consult local authorities.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Rio Mondego - Portugal Terrain map
About this water
Water quality (WFD)
- Ecology: Good
- Chemical: Good
What this classification means
WFD re-coded 2026-06-18: prior id PT04MON0614 actually identifies the Rio Seia — this river was mis-tagged to a neighbouring water body. Re-mapped to PT04MON0606. Status: EEA WISE 2022 (3rd RBMP). Confidence: medium — VERIFY upper-Mondego reach. Source: discodata.eea.europa.eu.
WFD classification · PT04MON0606
The full read · show the working · for Brown Trout · confidence 90%
How the 0 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time45 × 13%5.9
Pressure80 × 7%5.6
Insect activity45 × 12%5.4
Limiting factor: Water temperature (22°C) is outside Brown Trout's preferred range (10–16°C)= 49
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 March → 31 July
Related guides
Booking & contacts
Mondego (Upper Basin)
Upper Mondego rising in the Serra da Estrela flows through mountain water with wild brown trout.
Water temperature for Brown Trout
Warm — slow22°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
Water at 22°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayPeak at 6am
Hatch predictions
Today's headline hatch shown — see all 2 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 2 with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Survey-backed · regionalModerate 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
1
Large Dark OliveHatch
1
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Autumn OliveHatch
1
2
1
GrannomHatch
1
1
Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.
Ranked for today
Brown Trout fly box
A wild brown trout pack for northern and mountain Portugal. River-first, compact, and practical, with nymphs leading and dry flies taking over in the stronger windows.
14-18 · Pattern
Upstream dry, on top
6-10 · Pattern
Swing, sub-surface
Permits & access
Permit required — see local rules.
- Licença de Pesca Desportiva (Portuguese fishing license)
- Regional variation; consult local authorities.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
Rio Mondego - Portugal Terrain map
About this water
Upper Mondego rising in the Serra da Estrela flows through mountain water with wild brown trout. The upper basin above Nelas has the best fly fishing. Spring and early summer are the working months before heat arrives.
- Granite
Water quality (WFD)
- Ecology: Good
- Chemical: Good
What this classification means
WFD re-coded 2026-06-18: prior id PT04MON0614 actually identifies the Rio Seia — this river was mis-tagged to a neighbouring water body. Re-mapped to PT04MON0606. Status: EEA WISE 2022 (3rd RBMP). Confidence: medium — VERIFY upper-Mondego reach. Source: discodata.eea.europa.eu.
WFD classification · PT04MON0606
The full read · show the working · for Brown Trout · confidence 90%
How the 0 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time45 × 13%5.9
Pressure80 × 7%5.6
Insect activity45 × 12%5.4
Limiting factor: Water temperature (22°C) is outside Brown Trout's preferred range (10–16°C)= 49
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 March → 31 July
Related guides
Booking & contacts