Skagit River At Marblemount
Skagit River · Pacific NW · USGS gage 12181000
Coldwater (summer mean 11.8°C — prime coldwater).
Water
51°F
Flow
4,410 cfs
Air
56°F
Sky
93%
Pressure
30.05 in
Wind
2 mph
Predicted hatches · 2026-09-15
PredictedBlue-Winged OliveBaetis spp.0.57
Predicted by conditions; no reports yet. water 10.8°C (51°F) sits in the prime band (6-11°C); shoulder of the season; 8 days sustained ≥4°C; overcast skies favor it; watch midday, especially overcast afternoons.
flies: BWO Sparkle Dun #18-22, RS2, Pheasant Tail #18
PredictedMidgeChironomidae0.43
Predicted by conditions; no reports yet. water 10.8°C (51°F) is cooling past the prime band (1-10°C); shoulder of the season; 8 days sustained ≥0°C; watch midday, especially cold months.
flies: Zebra Midge #18-22, Griffith's Gnat, Disco Midge
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.