Tennessee Nature Guide: September 2026
Data updated: August 2026Sources & method · Corrections
September turns Tennessee toward fall — the monarch migration funnels down the ridges and the Mississippi corridor, hawks stream past the Cumberland Plateau overlooks, goldenrod and asters gild the meadows, and the sorghum and apple harvests fill the mountain festivals. The first cool nights break the summer heat, and the earliest color touches the high Smokies.
Week by week in September
September 3–9
- The fall warbler wave peaks in muted plumage and Broad-winged Hawks stream over in kettles along the plateau.
- Goldenrods and a dozen asters take over the meadows in a sweep of yellow and purple.
- New-season apples arrive from the Cumberland Plateau orchards and muscadine grapes hit their peak.
September 10–16
- Monarchs stream south in force, roadside goldenrod stands alive with them on a good migration day.
- Fall sorghum syrup from the mountain festivals appears and the first winter squash and pumpkins reach the stalls.
- Scarlet Tanagers, grosbeaks, and thrushes drift south as the first White-throated Sparrows return.
September 17–23
- The autumnal equinox near September 22 evens day and night as the Andromeda Galaxy rides high in the east.
- The first fall color touches the highest Smokies — mountain ash reddens and yellow birch and beech begin to gold.
- Plant garlic and shallots for next summer, sow cover crops on empty beds, and set out new trees and shrubs.
September 24–30
- Broad-winged Hawks and migrant songbirds pour past the plateau overlooks as wintering kinglets and sparrows arrive.
- Cloudless sulphurs stream through and gulf fritillaries work the passionflower as the monarch migration continues.
- Pawpaws ripen in the bottoms and the cool-season greens and broccoli reach the fall markets.
Birds This Month
September is the height of fall migration across Tennessee. The warbler wave peaks — Tennessee, Magnolia, Bay-breasted, Blackburnian, Chestnut-sided, Black-throated Green, American Redstart, and many more pour through the treetops, trickier to identify in their muted fall plumage. Ruby-throated Hummingbirds are still abundant at feeders early in the month, then thin out as they push south. Broad-winged Hawks stream over in kettles, and the Cumberland Plateau and mountain overlooks make fine hawk-watching.
Migrant shorebirds still work the West Tennessee mudflats and reservoir edges, Common Nighthawks continue their evening streams south, and Bobolinks, Dickcissels, and sparrows move through the fields. Scarlet and Summer Tanagers, Rose-breasted Grosbeaks, vireos, and thrushes drift south through the woods, and Chimney Swifts gather in massive pre-migration roosts, spiraling into chimneys at dusk. The first returning wintering birds — White-throated Sparrows and Yellow-rumped Warblers — arrive late in the month as the season turns.
What's Blooming
September is Tennessee's golden month, when the goldenrods and asters take over the meadows, roadsides, and old fields in a sweep of yellow and purple. A dozen goldenrods bloom together — tall, gray, and showy — alongside masses of New England aster, calico aster, white heath aster, and the late-flowering frost aster. Ironweed and joe-pye weed still hold deep violet and rose, and the prairies blaze with blazing star, gray-headed coneflower, and tall coreopsis.
The state wildflower, the passionflower (maypop), ripens its egg-shaped fruits along the fencerows, and along the streambanks the last cardinal flower and great blue lobelia linger. Jewelweed hangs orange in the wet bottoms, drawing the migrating hummingbirds, and trumpet creeper and wild morning glory climb the field edges. In the cedar glades of the Central Basin the late glade flora flowers in the thinning light, and the pollinator gardens hum with bees and the building monarch migration over the goldenrod and asters.
Garden This Month
September is the relief month in the Tennessee garden, when cooler nights ease the heat and the fall crops surge. The summer garden gives its last big harvest — pick the final tomatoes, peppers, okra, southern peas, melons, and winter squash, and pull spent plants to clean up the beds. The fall garden hits its stride: harvest broccoli, cabbage, lettuce, spinach, and the first frost-sweetened greens, and keep succession-sowing fast crops like lettuce, spinach, radishes, and turnips.
It is the prime month for several lasting jobs. Plant garlic and shallots toward month's end for next summer's harvest, sow cover crops — crimson clover, winter rye, Austrian winter peas — on emptied beds to build the soil, and divide and replant perennials, peonies, and spring bulbs. Plant new trees and shrubs now, as fall planting gives roots a head start before winter. Keep the fall seedbed watered, and start watching the forecast for the first frost, which returns to the high plateau and mountains by early-to-mid October.
Zone 6b (Cumberland Plateau & East Tennessee valleys): the first frost can come by early-to-mid October here, so the window is shorter. Harvest the last warm-season crops ahead of frost, tend the maturing fall greens, and plant garlic and cover crops as beds open.
Zone 7a (Middle Tennessee & Nashville Basin): the cool-season garden thrives. Keep sowing lettuce, spinach, radishes, and turnips, harvest the fall brassicas as they size up, and plant garlic toward month's end for next summer.
Zone 7b (southern Middle & West Tennessee): the heat finally eases. Continue sowing greens and root crops, set out a last round of lettuce and spinach transplants, and enjoy a long, productive fall before the late-October frost.
What's at the Farmers Market
September shifts Tennessee's markets toward the fall harvest while summer's last crops hang on. The headline crop is the apple — crisp new-season fruit from the Cumberland Plateau and East Tennessee orchards — and the fall sorghum syrup, cooked down at the mountain sorghum festivals, begins to appear. Muscadine and scuppernong grapes are at their peak, with their thick, slip skins.
The tables still carry late-summer tomatoes, peppers, okra, eggplant, sweet corn, and melons, now joined by the fall crowd — winter squash, pumpkins, sweet potatoes, greens, and the first fall lettuces and broccoli. Look for fresh pawpaws from the bottoms, cut flowers, and local honey. Choose apples that are firm and heavy with no bruises and store them cold, away from other produce, where they keep for months. Pick muscadines that are plump, dry, and unbruised and refrigerate them, eating within several days. Cure winter squash with hard rinds in a warm spot, then store cool and dry.
Night Sky This Month
September's clear, cooling nights are excellent at Tennessee's dark-sky places. Pickett CCC Memorial State Park and Pogue Creek Canyon, the International Dark Sky Park on the northern Cumberland Plateau, the high Great Smoky Mountains overlooks, and the Bays Mountain Park observatory near Kingsport run fall public viewing. The autumnal equinox near September 22 evens day and night, and the lengthening evenings bring earlier stargazing.
The sky is in transition. The Summer Triangle still rides high overhead with the Milky Way pouring through it, but the fainter autumn constellations are climbing the east — the Great Square of Pegasus, the chained figures of Andromeda and Cassiopeia's W, and within them the Andromeda Galaxy, the farthest object visible to the naked eye, an easy binocular smudge under dark plateau skies. Low in the south the dim water constellations spread out, and the Pleiades rise in the late-evening east, heralding winter. The printable Tennessee night-sky guide gives this year's planet positions and the best dark-sky sites for your region.
Butterflies & Pollinators
September is the great monarch migration month in Tennessee. The migratory super-generation streams south through the state all month, funneling down the Cumberland Plateau ridgelines and the Mississippi and Tennessee River corridors, nectaring heavily on goldenrod, asters, ironweed, and joe-pye weed to fuel the long flight to the fir forests of central Mexico. Roadside and prairie goldenrod stands can be alive with them on a good migration day.
The rest of the late-season fauna is still strong over the blooming meadows: cloudless and orange sulphurs stream through, gulf fritillaries work the passionflower of the west and middle of the state, common buckeyes, painted and American ladies, fiery and other skippers, and the last eastern tiger and spicebush swallowtails nectar at the asters. The question marks and eastern commas that will overwinter as adults are on the wing now, fattening up before hibernation. Leave the goldenrod, asters, and ironweed standing — they are the fuel that powers the monarch migration through Tennessee.
What to plant for them is in the Tennessee native plants guide
Trees This Month
September begins Tennessee's long, spectacular autumn, the color starting high and early. In the Great Smoky Mountains the first turning appears at the highest elevations — the mountain ash reddens its berry clusters on the spruce-fir summits, the yellow birch and American beech begin to gold, and the blackgum (tupelo) and sourwood flare the season's first scarlet across all elevations, always the earliest trees to turn.
The year's nut crop ripens and falls — hickory nuts, oak acorns, and husked black walnuts drop to feed the deer, turkeys, and squirrels stocking up for winter, and the persimmons soften toward ripeness after the first frost. The dogwoods redden their leaves and set their glossy red fruit, and the eastern red cedar of the glades hangs heavy with powder-blue cones for the waxwings and robins. Along the western rivers and at Reelfoot Lake the bald cypress just begin to bronze. The lowland forests still hold their summer green, but the turning has clearly begun in the high country.
The Tennessee native plants guide covers what grows with them
Weather & Daylight
Across Tennessee, a typical September day averages a high near 82°F and a low near 59°F, with about 3.9 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Summer loosens its grip, afternoons in the low 80s and cooler nights, with a drier, more settled stretch of weather.
| Average high | 82°F |
|---|---|
| Average low | 59°F |
| Precipitation | 3.9 in |
| Sunrise (mid-month) | 6:27 CT |
| Sunset (mid-month) | 18:54 CT |
Figures are statewide averages over the 1991–2020 U.S. climate normals; local conditions vary with elevation and distance from the coast. Sunrise and sunset are computed for a midstate point on the 15th (CT).
Next month's version of this page, by email
One short note when Tennessee's next month turns — what's arriving, blooming, and worth a night outside.
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The complete Tennessee birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: September in Texas · September in Utah · September in Vermont