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Hatch MatchHook the Horizon · field intelligence

Reference windows · not a forecast

When these groups are typically around.

Every band below is a published typical range. Elevation, latitude, aspect, tailwater release, drought and this particular year all move them — often by weeks. Read it as a map of the ordinary, then go look at the water.

This is not a hatch forecast. Nothing here knows your water, your elevation, or today. It cannot tell you what is emerging right now, and it never will.
Seventeen of the thirty-nine groups have a window here, and seven more have no season to have. The remaining fifteen have reviewed records and drawn plates but no seasonality yet — in some cases because the published sources genuinely do not support one. Cranefly larvae run anywhere from a few months to five years and turn up in spring, summer and autumn; black flies hold three different voltinism strategies inside one family across the whole year. There is no honest family-level window for either, so neither has one. That is a gap in this page, not a claim that they have no season, and their entries carry what the record does know.

Full year

Every window at once.

Typical availability windows by group, stage and month
Group · event
Midge (non-biting)Available year-roundJan: typical, prominentFeb: typical, prominentMar: typical, prominentApr: typical, prominentMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: typical, prominentNov: typical, prominentDec: typical, prominent
Midge (non-biting)EmergenceJan: typical, prominentFeb: typical, prominentMar: typical, prominentApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: typical, prominentDec: typical, prominent
Midge (non-biting)Surface clustersJan: typical, regularFeb: typical, regularMar: typical, regularApr: typical, regularMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: typical, regularNov: typical, regularDec: typical, regular
MayflyAvailable year-roundJan: typical, prominentFeb: typical, prominentMar: typical, prominentApr: typical, prominentMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: typical, prominentNov: typical, prominentDec: typical, prominent
MayflySpring emergenceJan: outside typical rangeFeb: outside typical rangeMar: typical, prominentApr: typical, prominentMay: typical, prominentJun: typical, prominentJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
MayflySummer emergenceJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: outside typical rangeJun: typical, regularJul: typical, regularAug: typical, regularSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
MayflyAutumn emergenceJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: typical, regularOct: typical, regularNov: typical, regularDec: outside typical range
MayflySpinner fallJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, regularMay: typical, regularJun: typical, regularJul: typical, regularAug: typical, regularSep: typical, regularOct: outside typical rangeNov: outside typical rangeDec: outside typical range
CaddisflyAvailable year-roundJan: typical, prominentFeb: typical, prominentMar: typical, prominentApr: typical, prominentMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: typical, prominentNov: typical, prominentDec: typical, prominent
CaddisflyEmergenceJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, prominentMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: outside typical rangeNov: outside typical rangeDec: outside typical range
CaddisflyEgg-layingJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: outside typical rangeNov: outside typical rangeDec: outside typical range
StoneflyAvailable year-roundJan: typical, prominentFeb: typical, prominentMar: typical, prominentApr: typical, prominentMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: typical, prominentNov: typical, prominentDec: typical, prominent
StoneflyPre-emergence migrationJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, prominentMay: typical, prominentJun: typical, prominentJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
StoneflyAdult activityJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
StoneflySmall winter speciesJan: typical, occasionalFeb: typical, occasionalMar: typical, occasionalApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
HellgrammiteAvailable year-roundJan: typical, regularFeb: typical, regularMar: typical, regularApr: typical, regularMay: typical, regularJun: typical, regularJul: typical, regularAug: typical, regularSep: typical, regularOct: typical, regularNov: typical, regularDec: typical, regular
Terrestrials (ants, beetles, hoppers)Bank fallsJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: outside typical rangeJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: outside typical rangeNov: outside typical rangeDec: outside typical range
Terrestrials (ants, beetles, hoppers)Flying-ant fallsJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: typical, regularAug: typical, regularSep: typical, regularOct: outside typical rangeNov: outside typical rangeDec: outside typical range
Baitfish / forage silhouetteForage present year-roundJan: typical, regularFeb: typical, regularMar: typical, regularApr: typical, regularMay: typical, regularJun: typical, regularJul: typical, regularAug: typical, regularSep: typical, regularOct: typical, regularNov: typical, regularDec: typical, regular
Damselfly / DragonflyNymphs available year-roundJan: typical, regularFeb: typical, regularMar: typical, regularApr: typical, regularMay: typical, regularJun: typical, regularJul: typical, regularAug: typical, regularSep: typical, regularOct: typical, regularNov: typical, regularDec: typical, regular
Damselfly / DragonflyAdult huntingJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: typical, prominentJun: typical, prominentJul: typical, prominentAug: typical, prominentSep: typical, prominentOct: outside typical rangeNov: outside typical rangeDec: outside typical range
Aquatic beetlesDiving / whirligig adultsJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, regularMay: typical, regularJun: typical, regularJul: typical, regularAug: typical, regularSep: typical, regularOct: typical, regularNov: outside typical rangeDec: outside typical range
Aquatic beetlesLarvae among vegetationJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, occasionalMay: typical, occasionalJun: typical, occasionalJul: typical, occasionalAug: typical, occasionalSep: typical, occasionalOct: outside typical rangeNov: outside typical rangeDec: outside typical range
Alewife / river herringSpawning runJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: typical, prominentJun: typical, prominentJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
Alewife / river herringYoung move seawardJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: typical, regularAug: typical, regularSep: typical, regularOct: typical, regularNov: typical, regularDec: outside typical range
Shad (gizzard and threadfin)Spring spawningJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, regularMay: typical, regularJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
Menhaden (bunker, pogy)Inshore seasonJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: typical, regularJun: typical, regularJul: typical, regularAug: typical, regularSep: typical, regularOct: typical, regularNov: outside typical rangeDec: outside typical range
Cisco / lake herringLate-autumn spawningJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: typical, regularDec: typical, regular
Inshore squidInshore seasonJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, regularMay: typical, regularJun: typical, regularJul: typical, regularAug: typical, regularSep: typical, regularOct: typical, regularNov: outside typical rangeDec: outside typical range
Inshore squidOffshore for winterJan: typical, occasionalFeb: typical, occasionalMar: typical, occasionalApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: typical, occasionalDec: typical, occasional
Alderfly larvaLarvae leave the waterJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: typical, regularMay: typical, regularJun: typical, regularJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
HellgrammiteLargest larvae leave the waterJan: outside typical rangeFeb: outside typical rangeMar: outside typical rangeApr: outside typical rangeMay: typical, regularJun: typical, regularJul: typical, regularAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: outside typical range
Water boatmenOverwinter in the waterJan: typical, regularFeb: typical, regularMar: typical, regularApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: typical, regularDec: typical, regular
BackswimmersOverwinter in the waterJan: typical, occasionalFeb: typical, occasionalMar: typical, occasionalApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: typical, occasionalDec: typical, occasional
Aquatic beetlesPresent under iceJan: typical, occasionalFeb: typical, occasionalMar: outside typical rangeApr: outside typical rangeMay: outside typical rangeJun: outside typical rangeJul: outside typical rangeAug: outside typical rangeSep: outside typical rangeOct: outside typical rangeNov: outside typical rangeDec: typical, occasional

outside the typical rangeoccasionalregularprominent

Shading is relative prominence within this reference set — how much of the season a group is usually a factor, not how likely it is to be hatching on your water today. Nothing here is a probability.

Month view

Typically around in Sep.

Midge (non-biting) — Available year-roundlarva

Chironomid larvae are present in almost every month in most cold water. They do not emerge to become available — they already are.

Temperature not the driver · All day

Open the Midge (non-biting) entry →
Mayfly — Available year-roundnymph

Nymphs are present continuously. Drift density rises in the hours before an emergence window.

Temperature not the driver · All day, with a pre-emergence increase in drift

Open the Mayfly entry →
Caddisfly — Available year-roundlarva

Cased and free-living larvae are present continuously; free-living forms are more available in the drift.

Temperature not the driver · All day

Open the Caddisfly entry →
Caddisfly — Emergencepupa

Pupae rise fast and actively rather than drifting up. That is the mechanism people reach for when a dead-drifted fly gets refused and a rising one does not — a reasonable read of how the insect moves, and not something this reference has watched happen.

50–62 °F · Afternoon into dusk

Open the Caddisfly entry →
Caddisfly — Egg-layingadult

Females may dive or crawl underwater to lay. A sunk adult is normal behaviour, not an anomaly.

52–68 °F · Dusk, and the hour after

Open the Caddisfly entry →
Stonefly — Available year-roundnymph

Large species live one to three years underwater, so a big nymph is available in every month of that span.

Temperature not the driver · All day; migration to the margins before emergence

Open the Stonefly entry →
Terrestrials (ants, beetles, hoppers) — Bank fallsadult

Hoppers, ants and beetles fall from the bank. This is not a hatch. Typical summer/early-autumn range only — wind and meadow height matter more than the calendar.

58–78 °F · Warm, windy afternoons; after flights

Open the Terrestrials (ants, beetles, hoppers) entry →
Damselfly / Dragonfly — Adult huntingadult

Adult Odonata hunt over still and slow water in the warm months. Not a current-emergence claim.

55–80 °F · Warm daylight over stillwater and slow margins

Open the Damselfly / Dragonfly entry →
Mayfly — Autumn emergencesubimago

Autumn windows narrow and centre on the warmest hours. Typically smaller-bodied than spring.

45–58 °F · Midday

Open the Mayfly entry →
Mayfly — Spinner fallspinner

Follows an emergence by roughly a day. Spent spinners lie flush and are easy to miss even when they are the only thing on the water.

Temperature not the driver · Dusk, occasionally first light

Open the Mayfly entry →
Hellgrammite — Available year-roundlarva

Larvae live one to three years under rock in riffles. They never emerge into the water column — they crawl out to pupate on land.

Temperature not the driver · All day; more active at night

Open the Hellgrammite entry →
Terrestrials (ants, beetles, hoppers) — Flying-ant fallsadult

Winged ants may raft after a nuptial flight. Reference only; a fall is a weather event, not a season you can schedule.

62–80 °F · Still, humid afternoons

Open the Terrestrials (ants, beetles, hoppers) entry →
Baitfish / forage silhouette — Forage present year-roundadult

Forage fish are not a hatch. Availability is continuous where they live. This window exists so a school is not forced into an insect calendar.

Temperature not the driver · All day; often tighter to cover in bright light

Open the Baitfish / forage silhouette entry →
Damselfly / Dragonfly — Nymphs available year-roundnymph

Damselfly and dragonfly nymphs overwinter. They are present long before adults hunt the margins.

Temperature not the driver · All day among vegetation and substrate

Open the Damselfly / Dragonfly entry →
Aquatic beetles — Diving / whirligig adultsadult

Adult water beetles are present across the ice-free season. They do not hatch in the mayfly sense.

48–75 °F · All day; whirligigs on the film, divers in the column

Open the Aquatic beetles entry →
Alewife / river herring — Young move seawardyoung-of-year

The year's young drop back down through the second half of the season at roughly 32–152 mm — which is the size range that matters to anything hunting them.

Temperature not the driver · Not stated by the source

Scope — Dated from Maine.

Open the Alewife / river herring entry →
Menhaden (bunker, pogy) — Inshore seasonadult

Menhaden arrive inshore as the water warms and withdraw southward in autumn. Some contingents do not migrate at all and stay resident, so this window is not the same thing as presence inside it or absence outside it.

Temperature not the driver · Schooling near the surface while present

Scope — Arrival dated from Massachusetts; the northern edge of the range moves latest.

Open the Menhaden (bunker, pogy) entry →
Inshore squid — Inshore seasonadult

Longfin squid move inshore once coastal water is at least about 48 °F, larger animals first and smaller ones through the summer. No upper band is given here because no source read gives one.

Temperature not the driver · Not stated by the source

Scope — Dated from Massachusetts waters.

Open the Inshore squid entry →
Aquatic beetles — Larvae among vegetationlarva

Larvae crawl in vegetation and substrate. Absence of a portable case is part of the tell.

Temperature not the driver · All day

Open the Aquatic beetles entry →

No season to have

These never emerge, so they are never a timing decision.

Each of these completes its whole life cycle in the water. There is no winged stage, no hatch, and nothing to be early or late for. They are not in the matrix above because a twelve-month bar would say something stronger than any source consulted actually says.

  • Scud / Amphipod →

    Whole life cycle in the water, no winged stage, and no separate larval form — the young are small versions of the adults.

  • Aquatic sowbug →

    Young are brooded in a pouch and released as miniature adults, so there is no synchronised appearance of a new stage to key on.

  • Leech →

    Eggs are laid into a mucous cocoon in the water. There is no aerial stage and nothing that emerges.

  • Aquatic worms →

    Hatch from cocoons as small versions of the adults and never leave the water.

    One behaviour worth separating from a season: when oxygen is especially low they may come to the surface. That is a response to the water, not a stage in a life cycle, and it should not be read as one.

  • Freshwater snail →

    Eggs are laid in gelatinous cocoons in the water. No aerial stage, and therefore not a hatch-driven food item at any time of year.

  • Clam (small freshwater bivalve) →

    Sphaeriid clams brood their young internally and release fully formed miniature clams — no free larval stage. Mussels differ: their larvae are parasitic on fish gills, so a mussel's early life is spent on a fish rather than in the substrate.

  • Crayfish →

    Entirely aquatic, with no emergence of any kind.

    But a crayfish is not the same food item all year. Published life histories put mating in autumn and egg-laying in spring, and describe a small number of adult moults clustered by season — a soft crayfish is a different animal to eat than a hard one. The detailed moult schedule is documented for one species and must not be read as a calendar for the family.

Jump to a group

MayflyCaddisflyStoneflyMidge (non-biting)HellgrammiteScud / AmphipodTerrestrials (ants, beetles, hoppers)Baitfish / forage silhouetteDamselfly / DragonflyAquatic beetlesShad (gizzard and threadfin)Alewife / river herringCisco / lake herringShiners and minnowsYellow perch, young of yearSunfish, young of yearCrayfishLeechAquatic wormsSand lance (sand eel)SilversidesAnchoviesMenhaden (bunker, pogy)Mullet (young)Killifish (mummichog and striped killifish)SculpinShrimp (grass and penaeid)Mole crab (sand flea)Blue crab (young)Marine wormsInshore squidWater boatmenBackswimmersCranefly larvaeAquatic sowbugFreshwater snailClam (small freshwater bivalve)Alderfly larvaBlack fly larva