Free Resource · Updated 2026
The complete fly hatch chart for New Hampshire's wild brook trout streams, White Mountains freestone rivers, and landlocked salmon runs. From the Swift River's June Green Drake hatch to the Androscoggin, Saco, Pemigewasset, and Connecticut River — select your stream below for peak hatch timing, fly pattern recommendations, and current month highlights for 2026.
New Hampshire Hatch Calendar — Quick Reference
Identifying the hatch is vital, but most days require versatile patterns that trigger strikes even when the water looks quiet. For a curated list of high-percentage patterns that belong in your box year-round, see our guide to the best trout flies in New Hampshire, featuring our top 5 essential picks for these waters.
New Hampshire Streams
Swift River · Ellis River · Mad River · Cold River
High-gradient, cold-water streams draining the White Mountains push hatch timing 1–2 weeks later than lower-elevation rivers. The Quill Gordon and Hendrickson arrive in early-to-mid May. Green Drakes peak in mid-June. These streams hold wild brook trout in the headwaters and brown trout in the lower reaches — they fish best once spring runoff clears, typically mid-May through June.
Androscoggin · Saco · Ammonoosuc · Pemigewasset
Larger drainages with diverse species including brown trout, brook trout, and landlocked salmon. Hatch timing is slightly earlier than the smaller mountain streams but still runs late compared to southern New England. The Androscoggin supports excellent Isonychia fishing in September that draws dedicated anglers statewide. Flows and temperatures fluctuate more than tailwaters, making timing critical.
Connecticut River · Contoocook River
Lower elevation and more moderate temperatures extend the season at both ends. The Connecticut River along the NH/Vermont border offers earlier spring hatches and consistent Sulphur and Trico fishing into summer. The Contoocook holds good populations of wild browns and produces reliable hatch activity from Quill Gordon through Autumn Caddis, with Isonychia being a September highlight.
The Why Behind the Chart
Epeorus pleuralis
New Hampshire's first significant mayfly hatch and a signal that the dry fly season has opened. Quill Gordons emerge in the afternoon when water temps climb into the mid-to-upper 40s°F — typically between 2–4pm on warm, sunny days in late April. On mountain streams the hatch may not fire until the first week of May. Trout that have been reluctant to surface all winter commit to these early-season dries with surprising aggression. A quartering upstream presentation into riffles and pocket water is the classic approach.
Recommended: #12–14 Quill Gordon Dry, Hare's Ear Nymph
Ephemerella subvaria
The Hendrickson follows the Quill Gordon and is the most widely distributed major hatch in New Hampshire — present on virtually every quality trout stream in the state. It fires in the early-to-mid afternoon when skies are overcast and water temps are in the low-to-mid 50s°F. On lower-elevation rivers like the Contoocook and Connecticut it may arrive in late April; on White Mountains streams it typically fires the first two weeks of May. Fish the dun in the film with a downstream-and-across drift through flat water and slow runs.
Recommended: #12–14 Hendrickson Comparadun, A.P. Nymph
Ephemera guttulata
New Hampshire's most anticipated hatch and the highlight of the dry fly calendar. Green Drakes fire at dusk when water temps reach 55–62°F — on NH's cooler rivers this typically means mid-June rather than late May as in Pennsylvania. The Swift River's Albany Covered Bridge section on the Kancamagus Highway is one of the most scenic and productive Green Drake venues in New England. Large brown trout that are rarely visible during the day rise freely after 7pm. Bring a headlamp — the spinner fall after dark can be the best fishing of the year.
Recommended: #8–10 Green Drake Wulff, Coffin Fly spinner
Stenacron interpunctatum
A reliable evening hatch that bridges the gap between the major spring mayflies and summer fishing on most NH rivers. Light Cahills appear in the evening when temps warm in June and run into July. They are present on nearly every NH trout stream and produce consistent dry fly action across different current types — riffles, runs, and the edges of flats. Tie on a #12–14 Light Cahill Comparadun and fish rising fish in the flats and glides as the light fades. A good hatch to build confidence on if you're new to New Hampshire streams.
Recommended: #12–14 Light Cahill Comparadun, EHC
Isonychia bicolor
One of the most underrated hatches in New England and a September staple on New Hampshire's larger freestone rivers. Isonychia — also called Slate Drakes — are big (#10–12), fast-swimming nymphs that trout pursue aggressively before the dun emerges. The dun hatch fires in late afternoon and continues into evening. On the Androscoggin and Contoocook, September Isonychia action can rival anything the summer offered. Swing a soft hackle or wet fly down and across to imitate the emerging nymph — it's one of the few times a downstream presentation consistently outfishes the upstream dry.
Recommended: #10–12 Isonychia Comparadun, Soft Hackle Wet Fly
Baetis sp.
NH's most dependable all-season hatch — present spring and fall on every stream type and most reliable on overcast, drizzly days when other hatches won't cooperate. Spring BWOs peak in April; the fall window is September through November. Unlike warmer-state rivers, NH's fall BWO hatches can fire on cold, raw October afternoons that drive most anglers off the water. When the weather turns ugly and the thermometer drops, tie on a #18–22 Sparkle Dun or RS2 and look for rising trout in flat water. This is when you'll often have the river to yourself.
Recommended: #18–22 Sparkle Dun, RS2 emerger
New Hampshire's trout season opens with Quill Gordon and Hendrickson hatches in late April and May — classic New England dry fly fishing on freestone streams running cold and clear from snowmelt. Blue-Winged Olives fish well throughout spring and fall across all stream types, and are especially productive on overcast days when nothing else is happening.
June is NH's peak hatch month. The Green Drake (Ephemera guttulata) hatch fires at dusk on major rivers including the Swift, Saco, Androscoggin, and Pemigewasset — a brief but spectacular event that draws anglers from across New England. Light Cahills provide reliable evening action through June and July on virtually every NH trout stream. Summer also brings occasional Sulphur and Trico hatches on lower-elevation and larger rivers.
Fall is underrated in New Hampshire. Isonychia hatches on the Androscoggin and Contoocook in September produce some of the year's best dry fly fishing, and Autumn Caddis combined with BWOs extend quality surface action through October. Use FlyFishFinder's flow alerts to know when your target NH stream is at prime level and dropping into fishable range.
See Live New Hampshire River Conditions →Common Questions
The Quill Gordon is New Hampshire's first major mayfly hatch, typically firing in late April when water temps reach 45–50°F on afternoon sunny days. On smaller, higher-elevation streams like the Swift River and Ellis River it may push into early May. The hatch fires mid-afternoon, around 2–4pm, and can be remarkably dense for a brief window each day.
May is NH's transition month — Quill Gordons fade and Hendricksons take over as the dominant dry fly hatch. Carry #12–14 Hendrickson Comparaduns and A.P. Nymphs, a #12–14 Quill Gordon for the overlap period, and #16–18 BWO Sparkle Duns for overcast days. A Pheasant Tail or Hare's Ear nymph fished in the film will cover you between hatches.
The Swift River (Albany Covered Bridge section, Kancamagus Highway) fishes best from late April through June for dry flies, and again in September and October for BWOs and Autumn Caddis. The Green Drake hatch in mid-June is the highlight of the year on the Swift. It's a freestone stream, so high runoff in April and May can muddy the water — wait for flows to clear.
White Mountains streams (Swift River, Ellis River, Mad River) run cold and high in May, pushing hatches 1–2 weeks later than lower-elevation rivers like the Contoocook or Connecticut River. The Green Drake peaks in June on mountain streams vs. late May elsewhere. Expect Quill Gordons and Hendricksons to arrive noticeably later at higher elevations.
The Androscoggin is a larger freestone river in northern NH with brook trout, brown trout, and landlocked salmon. Focus on Green Drake Wulffs and Comparaduns in June, Light Cahills through July, Isonychia Comparaduns in September, and BWO Sparkle Duns spring and fall. Streamers — especially Woolly Buggers and small Clousers — work well for salmon in early spring before the major hatches begin.
June is NH's peak hatch month — Green Drakes, Light Cahills, and Sulphurs overlap on many rivers. May brings the Hendrickson and Quill Gordon hatches on most streams. September is an underrated month for Isonychia and Autumn Caddis with fall foliage as a backdrop. April and October offer reliable BWO fishing on overcast days across nearly every NH trout stream.
FlyFishFinder combines hatch knowledge with live gauge alerts, Prime condition indicators, and real angler intel — so you show up on the right day, not the wrong one.
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