Flathead River At Columbia Falls
Flathead River · Rockies · USGS gage 12363000
Coldwater (summer mean 13.8°C — prime coldwater; very large river (17,700 cfs)).
Water
52°F
Flow
18,000 cfs
Air
60°F
Sky
100%
Pressure
29.91 in
Wind
5 mph
Predicted hatches · 2026-06-18
PredictedGreen DrakeDrunella spp.1.00
Predicted by conditions; no reports yet. water 11.2°C (52°F) sits in the prime band (11-15°C); peak season; 5 days sustained ≥10°C; watch midday, often cloudy.
flies: Green Drake Parachute #10-12, Cripple, Hares Ear #10
PredictedMidgeChironomidae0.40
Predicted by conditions; no reports yet. water 11.2°C (52°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.