Fly fishing hatch timing
Hatch calendars for the top 50 Eastern US trout rivers.
Month-by-month timing for every major hatch — Sulphurs, Green Drakes, Hendricksons, BWOs, October Caddis, Trico spinner falls — across the states we cover. Each calendar lists peak windows, fly patterns, water temperature triggers, and time of day.
A note on hatch timing
Hatches respond to water temperature, not the calendar. A cold spring can push everything back two weeks; a warm spell can collapse two hatches into one. Cross-reference with a local fly shop before planning a trip.
What's hatching now
June on the water.
Top eight rivers right now by aggregate hatch intensity.
Pennsylvania
Upper Delaware River
- Midgeheavy
- Sulphurheavy
New York
West Branch Delaware River
- Midgeheavy
- Sulphurheavy
Pennsylvania
Penns Creek
- Midgeheavy
- Sulphurheavy
Pennsylvania
Big Fishing Creek
- Sulphurheavy
- Midgemoderate
Pennsylvania
Brodhead Creek
- Sulphurheavy
- Midgemoderate
New York
Beaverkill River
- Sulphurheavy
- Slate Drakeheavy
Virginia
Jackson River
- Midgeheavy
- Sulphurheavy
North Carolina
Nantahala River
- Midgeheavy
- Sulphurheavy
Hatch types
- Mayfly
- Caddis
- Stonefly
- Midge
- Terrestrial
18 species tracked across five hatch types, with peak windows and water-temperature triggers.