Colorado River Near Granby
Colorado River · Rockies · USGS gage 09019500
Coldwater (summer mean 9.6°C — prime coldwater).
Water
53°F
Flow
74 cfs
Air
50°F
Sky
4%
Pressure
29.82 in
Wind
3 mph
Predicted hatches · 2026-09-15
ConfirmedBlue-Winged OliveBaetis spp.0.55
Model says likely and 1 recent report confirm it. water 11.5°C (53°F) is cooling past the prime band (6-11°C); shoulder of the season; 7 days sustained ≥4°C; watch midday, especially overcast afternoons.
reports: Orvis — Colorado River Reports
flies: BWO Sparkle Dun #18-22, RS2, Pheasant Tail #18
ConfirmedMidgeChironomidae0.51
Model says likely and 1 recent report confirm it. water 11.5°C (53°F) is cooling past the prime band (1-10°C); shoulder of the season; 7 days sustained ≥0°C; watch midday, especially cold months.
reports: Orvis — Colorado River Reports
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.