Michigan Phenology

Saginaw Bay to the AuSableSummer

Tuesday, June 2, 2026.

AuSable
1020 cfs
↘ dropping
Water
59 °F
river
Season
on time
273 GDD
Moon
92 %
waning gibbous
Daylight
15:14
+1.3 min/day
Hatching: Grannom caddis, Hendrickson, Spongy moth egg hatch Plant now: Peas, Spinach and lettuce, Radish and arugula Overhead: Ursa Major
The read

The AuSable is at 1020 cfs, near the 906 cfs median for the date, dropping over the past two days, and 59 degrees F. The water sits in the prime window, so hatches and rises should come on the evening. Degree days stand at 273 against a normal of 283, so the season is essentially on schedule. Against the long-term normal, accumulated heat is running ahead by 79 growing degree days. The national spring index put first leaf-out near April 14 this year, right on the long-term normal. Daylight is 15 hours 14 minutes, still lengthening about 1.3 minutes a day, and the soil at six inches is 64 degrees, warm enough for morels and the warm-season garden. The region's average last frost, around mid-May, has passed. The March Brown and Sulphur is on now; the Hexagenia (Hex) projects to June 24, about 22 days out. Black locust bloom is the Isonychia and late Sulphur cue, and the all-clear for heat-loving crops. On the bay, 2 notable birds are being reported, including Stilt Sandpiper and Red Knot.

Correlation: Breeding bird peak song and White-tail fawning overlap on the calendar right now. Watch whether they track together as the years bank up.

JFMAMJJASOND
Tap any dot for the detail and projection.
Water and iceFishHatchesBirdsBloom and colorGarden, zone 6aWildlife

Happening now

Black locust bloomnow
Cream-white clusters, heavy and fragrant.
Brown Drake hatchnow
Big evening drakes, short and intense.
Warm-season transplanting, 6anow
Tomatoes, peppers, squash go to the bay garden.
White-tail fawningnow
Does bearing fawns in the forest.
Breeding bird peak songnow
Dawn chorus at full volume.
Monarch arrivalnow
First milkweed eggs.
March Brown and Sulphur hatchesnow
Steady afternoon and evening fishing.
Saginaw Bay NE wind seasonnow
Spring northeast winds, cold and steady, slow the bay warm-up.
Great Lakes seasonal peaknow
Lake Huron near its annual high.

Next three weeks

Saginaw Bay summer calm2 d
Light winds, warm bay, ideal for boating and surface life.
Fireflies emerge5 d
First flashes over the damp meadows.
Hexagenia (Hex) hatch10 d
The legendary AuSable night hatch.
Common milkweed bloom13 d
Pink heads humming with insects.

Just past

Morel season8 d ago
Warm soil under aspen and ash.
Warbler migration peak5 d ago
Tawas Point and the bay shoreline light up.
Last spring frost (median)8 d ago
Bay City median; tender crops wait until past.
Dandelion bloom3 d ago
The first broad nectar flow of spring.
Oak leaf-out, squirrel's ear11 d ago
New oak leaves about the size of a squirrel's ear.
Ruby-throated hummingbird arrival8 d ago
First at the feeders and the columbine.
Baltimore oriole arrival9 d ago
Orange in the treetops; hang orange halves and jelly.
Apple blossom6 d ago
Orchards in full flower.
Flowering dogwood bloom3 d ago
At the northern edge of its range here.

Connections in play

The signals nature is giving right now, and what each one points to on the rivers, in the woods, and in the garden.

Black locust bloomactive now
Black locust bloom is the Isonychia and late Sulphur cue, and the all-clear for heat-loving crops.
White-tail fawningactive now
Fawning season; does are protective and bedded, bucks are in bachelor groups recovering from spring.
Saginaw Bay NE wind seasonactive now
Spring NE winds cool the bay and slow the water warm-up, delaying walleye and supporting early fishing; in the garden, they slow growth and can damage young transplants.
Fireflies emergein about 5 days
Fireflies on warm nights run with the Hex on the rivers; high summer is here.
Common milkweed bloomin about 13 days
Milkweed in flower is monarch egg-laying peak and the richest nectar of the year.
Saginaw Bay summer calmin about 2 days
Summer calm waters and light winds are perfect for boating and garden growth, but walleye go deep seeking cool; focus structure and depth.
River:the home water
AuSable flowlive
1020cfs
USGS gauge, dropping
River waterlive
59deg F
AuSable, USGS
Lake Huron levellive
176.57m IGLD
Saginaw Bay, NOAA
Saginaw Bay windlive
15.7mph
out of the N, buoy 45203, 2.6 ft seas
Bay water, buoylive
61deg F
Saginaw Bay buoy 45203
Lake surface, satellitelive
59deg F
GLSEA whole-bay average, 2026-05-26

Hatch and emergence forecast

computed

This season's accumulated heat against known degree-day thresholds, with the aquatic hatches cross-checked against the live AuSable water temperature. Estimates, not promises; emergence shifts with the weather.

Grannom caddison now
the early black caddis blizzard
Hendricksonon now
afternoon emergence on cool days
Spongy moth egg hatchon now
caterpillars climbing oaks
Eastern tent caterpillaron now
tents in cherry and apple
Sulphurabout 2 days out
long evening spinner falls
Brown Drake~2 weeks out
big evening hatch, brief window
Emerald ash borer flight~2 weeks out
first adults emerge from ash
Isonychia~2 weeks out
fast water, much of the summer
Hexagenia limbata~4 weeks out
the Hex, after dark, the season's biggest
river 5 deg below the 64 trigger
Firefly peak~4 weeks out
field displays at dusk
Japanese beetle~6 weeks out
adults on roses and lindens
Trico~6 weeks out
tiny morning spinner falls
Dog-day cicada~9 weeks out
afternoon drone in the canopy
White Fly~9 weeks out
late-summer evening blizzard
river 3 deg below the 62 trigger