Boise River At Caldwell
Boise River · Rockies · USGS gage 13211205
Trout (marginal) (summer mean 20.4°C — trout, warm in summer).
Water
55°F
Flow
542 cfs
Air
49°F
Sky
100%
Pressure
29.85 in
Wind
4 mph
Predicted hatches · 2026-11-01
PredictedMidgeChironomidae0.29
water 12.5°C (55°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
PredictedBlue-Winged OliveBaetis spp.0.29
water 12.5°C (55°F) is cooling past 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
PREDICTED from the first-principles model only. Report-confirmed signal (fly-shop & forum reports) is the next milestone.