Colorado River Near Granby
Colorado River · Rockies · USGS gage 09019500
Coldwater (summer mean 9.6°C — prime coldwater).
Water
52°F
Flow
184 cfs
Air
65°F
Sky
0%
Pressure
29.85 in
Wind
4 mph
Predicted hatches · 2026-07-31
PredictedMidgeChironomidae0.52
Predicted by conditions; no reports yet. water 10.9°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.
reports: Orvis — Colorado River Reports
flies: Zebra Midge #18-22, Griffith's Gnat, Disco Midge
PredictedGreen DrakeDrunella spp.0.45
Predicted by conditions; no reports yet. water 10.9°C (52°F) is warming toward the prime band (11-15°C); shoulder of the season; 8 days sustained ≥10°C; watch midday, often cloudy.
flies: Green Drake Parachute #10-12, Cripple, Hares Ear #10
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.