Trinity River at Lewiston
Trinity River · Sierra / West · USGS gage 11525500
Coldwater (summer mean 11.1°C — prime coldwater).
Water
51°F
Flow
438 cfs
Air
85°F
Sky
0%
Pressure
29.88 in
Wind
6 mph
Predicted hatches · 2026-07-31
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
PredictedGreen DrakeDrunella spp.0.40
Predicted by conditions; no reports yet. water 10.8°C (51°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.