Trout Hatch Calendar

A seasonal trout hatch calendar covering mayflies, caddis, stoneflies, and midges — with life stages, the best time of day, and the months each hatch is active.

• Blue-winged Olive (Baetis tricaudatus) — Dun, best Midday to afternoon, especially on overcast days. Active: Mar, Apr, May, Sep, Oct, Nov.
• Caddisfly (Hydropsychidae) — Adult, best Evening, dusk into darkness. Active: Apr, May, Jun, Jul, Aug, Sep.
• Callibaetis (Callibaetis ferrugineus) — Dun, best Late morning. Active: Jun, Jul, Aug, Sep.
• Golden Stonefly (Claassenia sabulosa) — Adult, best Evening and night. Active: Jun, Jul.
• Green Drake (Drunella grandis) — Dun, best Afternoon, 2pm to 5pm. Active: Jun, Jul.
• March Brown (Rhithrogena morrisoni) — Dun, best Afternoon. Active: Mar, Apr, May.
• Midge (Chironomidae) — Emerger, best Midday when temperatures peak. Active: Jan, Feb, Mar, Oct, Nov, Dec.
• Midge Adult (Chironomidae) — Adult, best Warm midday hours. Active: Jan, Feb, Mar, Apr, Oct, Nov, Dec.
• PMD Emerger (Ephemerella dorothea) — Emerger, best Late morning, during hatch. Active: Jun, Jul, Aug.
• Pale Morning Dun (Ephemerella dorothea) — Dun, best Late morning, 10am to noon. Active: Jun, Jul, Aug.
• Salmon Fly (Pteronarcys californica) — Adult, best All day, most active late afternoon. Active: May, Jun.
• Trico (Tricorythodes minutus) — Spinner, best Early morning, 7am to 10am. Active: Jul, Aug, Sep.