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 temperature for brown trout
Warm — slow20°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 20°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots. Otherwise poor — water clarity is in the right range.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 4 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
ModelledModerate confidence
Modelled from regional ecology — no survey or occurrence data for this water yet.
Through the year
0–3 scale · July 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
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
Cooler water nearby · 1
Water here around 20°C — probably warm enough to stress brown trout. These are likely cooler.
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 80%
How the 28 is built — score × weight = contribution
Temperature25 × 28%7.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity50 × 12%6.0
Conditions total= 57
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
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
- Trout1 March → 31 July
Related guides
Booking & contacts
Mondego (Upper Basin)
Terrain map
Upper Mondego rising in the Serra da Estrela flows through mountain water with wild brown trout.
Water temperature for brown trout
Warm — slow20°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 20°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots. Otherwise poor — water clarity is in the right range.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 4 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
ModelledModerate confidence
Modelled from regional ecology — no survey or occurrence data for this water yet.
Through the year
0–3 scale · July 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
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
Cooler water nearby · 1
Water here around 20°C — probably warm enough to stress brown trout. These are likely cooler.
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 80%
How the 28 is built — score × weight = contribution
Temperature25 × 28%7.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity50 × 12%6.0
Conditions total= 57
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
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
- Trout1 March → 31 July
Related guides
Booking & contacts