Michigan Nature Guide: September 2026
September is the great turning of the Michigan year — fall migration crests, the first sugar maples and aspens flame in the north, and the monarchs stream down the lakeshores toward Mexico. The harvest swings to apples and squash as the air turns crisp.
What to look for this week
- Feeders are at their winter peak — black-capped chickadees, nuthatches, and cardinals work the seed, with redpolls and siskins possible in a northern-finch irruption year.
- The Quadrantid meteor shower peaks in a short, sharp burst around January 3; watch the northeast after midnight from a dark site away from city lights.
- A planning week — order seeds early, especially the short-season varieties northern Michigan gardens depend on, before they sell out.
Birds This Month
September is the second great birding month in Michigan, the mirror of May. Fall warbler migration peaks — dozens of species in subtler autumn plumage move through the woods, a quieter but richer flow than spring, joined by vireos, thrushes, flycatchers, tanagers, and the last orioles and grosbeaks. Sparrow migration builds late in the month, filling weedy edges with white-throated, white-crowned, and other migrants.
The headline is hawk migration: at the Straits of Mackinac, where the Mackinac Straits Raptor Watch tallies the fall passage, and along the Lake Erie and Lake Michigan shorelines, thousands of broad-winged hawks kettle and stream south, with sharp-shinned and Cooper's hawks, ospreys, bald eagles, kestrels, merlins, and peregrine falcons. Common nighthawks pour over at dusk early in the month, sandhill cranes mass into large flocks, and the last ruby-throated hummingbirds depart. Keep feeders up for late migrants. This is one of the most rewarding months of the year to be in the field.
What's Blooming
September is the climax of Michigan's fall wildflower bloom, dominated by the asters and the late goldenrods. The fields, roadsides, and prairies glow with the purple of New England aster, the white sprays of heath and panicled asters, the sky-blue of smooth aster, and the fading gold of goldenrod — together they form the most important late-season nectar source for the monarchs and bees fueling migration.
The wet meadows still hold great blue lobelia, turtlehead, late Joe-Pye weed, and closed (bottle) gentian, and the prairies carry the last blazing star, ironweed, and tall sunflowers. The grasses come into their own as the flowers fade — big bluestem, Indian grass, and little bluestem turn russet and gold and set their seed heads. In gardens, sedums, mums, and the last dahlias and zinnias carry the color. A prairie or old field in late September is awash in purple and gold and humming with the final pollinators of the year.
Garden This Month
September is the harvest-and-wind-down month in the Michigan garden, with the first frost looming — early in the north, near month's end in the south. Bring in the warm-season crops as they ripen: tomatoes, peppers, eggplant, melons, winter squash, sweet corn, and the last beans and cucumbers. When frost threatens, harvest tender crops or cover them, and pick green tomatoes to ripen indoors. Dig potatoes and cure winter squash and onions for storage.
It's also the prime month to set up next year: plant garlic and spring-flowering bulbs, sow cover crops (oats, winter rye) on cleared beds to protect and build the soil, and divide and plant perennials and trees while the soil is still warm and roots can establish before winter. Keep harvesting the cool-season crops — kale, chard, fall lettuce, and roots all sweeten in the cooling weather. Start cleaning up spent plants, but leave seed heads standing for the birds.
Zone 4b (interior north & eastern U.P.): the first frost can arrive early this month — harvest tender crops promptly, cover what you can on frost nights, and dig potatoes and cure winter squash before the cold sets in.
Zone 5b (much of the lower peninsula): the first frost typically nears month's end — keep harvesting, plant garlic and spring bulbs, sow a cover crop on cleared beds, and have row cover ready for early frosts.
Zone 6a (southwest lakeshore & far south): frost holds off longest here — keep harvesting warm crops, sow a last round of fast greens, and begin planting garlic and bulbs late in the month.
What's at the Farmers Market
September markets pivot from summer's bounty to autumn's harvest, and the headline is apples. Michigan is a leading apple state, and the fall varieties pour in — Honeycrisp, Gala, McIntosh, Jonagold, Empire, and more — along with fresh-pressed cider and the orchards' u-pick season in full swing. The first winter squash and pumpkins arrive, and grapes (concord and table) peak, perfuming the southwest fruit belt.
The summer crops finish strong early in the month — tomatoes, peppers, sweet corn, melons, eggplant, and beans — before the season's first frost. Cool-season vegetables return: broccoli, cauliflower, cabbage, kale, leeks, fall carrots, beets, and potatoes. Choose apples that are firm and heavy for their size and store them cold, where they'll keep for months; keep cider refrigerated and tightly capped. Cure winter squash with the stem on and store cool and dry. The markets are colorful, abundant, and unmistakably autumn.
Night Sky This Month
September brings the balance of the autumn equinox, lengthening nights, and the handoff from summer to fall constellations. Early in the evening the Summer Triangle still rides high, the Milky Way arcing through it, but the Great Square of Pegasus climbs in the east, leading the fall sky, and the Andromeda Galaxy — the most distant object visible to the naked eye — rides high enough to find with binoculars beside it. Cassiopeia's W stands prominent in the northeast.
There's no major meteor shower in September, but the comfortable nights and the still-glorious Milky Way make for excellent general stargazing, especially from the dark north. The Headlands near Mackinaw City and the Keweenaw Dark Sky Park offer Michigan's darkest skies, and as the nights cool and lengthen, the chance of aurora on the northern horizon rises with the autumn geomagnetic season. The printable Michigan night-sky guide lists this year's planet positions, viewing windows, and aurora outlook for your part of the state.
Butterflies & Pollinators
September is the month of the great monarch migration in Michigan. The super-generation that emerged in late summer now streams south by the thousands, funneling down the Lake Michigan and Lake Erie shorelines and concentrating at points and beaches where the water forces them to gather before crossing — places like the dunes of the western shore and the southeast lakefront. They cluster in trees to roost overnight and pour out on warm, sunny days, fueling on the blooming goldenrod and asters for the long flight to central Mexico.
Other migrants move too — painted ladies, red admirals, common buckeyes, and cloudless sulphurs drift south, and the clouded and orange sulphurs remain common over fields and clover. The resident cabbage whites, fritillaries, and late skippers linger into the cooling weather. The asters and goldenrods are the last great nectar source — leaving them standing supports the monarchs on their epic journey. Watching the migration along a Great Lakes beach on a sunny September day is one of the state's natural spectacles.
Trees This Month
September is when Michigan's famous fall color begins, sweeping south from the Upper Peninsula. The sugar maples light up first in the north — flaming orange, red, and yellow across the U.P. and the northern lower peninsula by mid-to-late month — joined by the brilliant gold of quaking aspen and paper birch and the deep red of red maple in wet ground. The drive corridors of the north fill with leaf-peepers as the color crests.
The tamaracks in the bogs begin their golden turn, the black gum and sumac flame scarlet, and the ashes turn maroon and yellow. The nut crop drops — acorns, hickory nuts, walnuts, and beechnuts rain down, a feast for jays, squirrels, turkeys, and deer. In the south, the color is just beginning, the canopy still mostly green. Peak in the north is late September; the lower peninsula's display builds toward early-to-mid October. It is the start of one of the great natural shows of the Michigan year.
Go deeper with the Michigan guides
The complete Michigan birding, native-plant, wildflower, and night-sky guides — or the whole year in one bundle.
Same month elsewhere: September in Minnesota · September in Mississippi · September in Missouri