Freestone · Limestone · Alps / Savoie-Isère border, FR

Guiers

A clear mountain stream flowing through the village of Saint-Pierre-dEntremont with alpine peaks behind, on the Guiers river system

1st-category river on the Savoie-Isère border with ~1.

Today · Closed season
Sculpin Streamer
Forecast · Today
Closed season
Out of season. Try elsewhere.
45% projected
Today's fly
Sculpin Streamer
Sculpin Streamer
Conditions on the water · Today
Live gauge
Level
Rising
1.03 m
Lifting fast
Water temp10.4°C
ClarityUnfishable
Weather6°C
WindN 13 km/h
Pressure1010 hPa
Rain · recent31.7 mm
Rain · ahead1.4 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
Ideal
10°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.
Hatch timeline · todayPeak at 11am

12pm(now) — Autumn Needle Fly

Stage: Creeping nymphsApproach: Heavy nymphActivity: 40%
Also:Autumn Olive21%
Peak emergence window4 food groups active

Peak activity at 11am — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 4 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Supporters see what else is on the menu.

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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 · November highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Grayling seasonSeason
1
2
2
2
1
Alpine RhithrogenaHatch
2
3
3
2
Sculpin / Baitfish (Rivers)Hatch
2
3
3
3
3
3
3
3
2
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2

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

Ranked for today
Brown Trout fly box

French nymph-first water. Fast current, technical presentation, weighted nymphs and emergers, with dry flies when fish rise.

Permits & access
Permit required — see local rules.
  • AAPPMA permits.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gelon
30 km
0
Brown trout · Grayling
Isère (Combe de Savoie)
37 km
0
Brown trout · Grayling
Lac d'Aiguebelette
12 km
Brown trout · Char
Pisciculture de Burcin - La pêche pour tous
22 km
Rainbow trout
Lac du Bourget
32 km
Brown trout · Char
Gallery · 2
  1. A clear mountain stream flowing through the village of Saint-Pierre-dEntremont with alpine peaks behind, on the Guiers river system
    The Guiers Vif at Saint-Pierre-d'Entremont, on the Savoie–Isère border
  2. Terrain map of the venue
    Terrain map
About this water

5 km no-kill course through limestone and alpine terrain where geology changes hands. Selective dry-fly water in pristine conditions. Spring through early autumn offers consistent fishing. Mountain character with responsive flow. Some sections may have specific regulations; verify with local AAPPMA.

Hatches & food

In true Alpine headwaters, trout feeding is squeezed into a short high-summer slot, with mountain olives and other mayflies following snowmelt, daytime stoneflies over rough, bouldery water, evening caddis on the warmest settled nights, and small buzzers keeping fish interested before, between and after the main up-wing and caddis hatches.

  • Limestone
Water quality (WFD)
  • Ecology: Moderate
  • Chemical: Unknown
What this classification means

WFD ecological status Poor → Moderate corrected to EEA WISE 2022 (3rd RBMP) classification for waterbody FRDR515 (was a stale earlier-cycle value). Source: EEA WISE SWB_SurfaceWaterBody (discodata.eea.europa.eu), verified 2026-06-18.

WFD classification · FRDR515

The full read · show the working · for Brown Trout · confidence 75%
How the 0 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow95 × 22%20.9
Clarity40 × 18%7.2
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity62 × 12%7.4
Conditions total= 78
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 2nd Saturday of March → 3rd Sunday of September
  • Grayling 3rd Saturday of May → 3rd Sunday of September

    France national rule: grayling opens 3rd Saturday of May in all waters. In 1st category (salmonid) rivers, grayling closes with the trout season on the 3rd Sunday of September. Departmental regulations may impose additional restrictions. Always check the relevant département's 2026 arrêté préfectoral.

Related guides
Grayling Playbookgrayling tacticsPyrenees PlaybookFrench riversEuro Nymphingsubsurface methods
Booking & contacts
At a glance

Guiers is a freestone river in Alps / Savoie-Isère border, France. The catchment geology is recorded as limestone, and the water sits at about 367 m above sea level. The river is described as roughly 50 km long. Species listed for this water: brown trout and grayling. The trout season is recorded as running from 2nd Saturday of March to 3rd Sunday of September. The grayling season is recorded as running from 3rd Saturday of May to 3rd Sunday of September. Best window recorded for anglers: May–September. Core methods listed: Nymphing; dry fly. Level and flow data for this water is linked from 1 gauge. Its Water Framework Directive ecological status is recorded as moderate. Access is recorded as day tickets through the local AAPPMA (angling association). Nearby waters in our listings include Lac d'Aiguebelette at 12 km, Pisciculture de Burcin - La pêche pour tous at 22 km and Gelon at 30 km.