Louisiana Nature Guide: September 2026
Data updated: August 2026Sources & method · Corrections
September turns the corner toward fall in Louisiana — the hummingbirds reach their roaring peak as they fuel for the Gulf crossing, hawks and migrants stream south, and the first cool fronts break the summer. The fall garden goes in, and the goldenrod begins to gild the prairies and cheniers.
Week by week in September
September 3–9
- Hummingbirds reach their roaring peak — coastal yards host dozens fueling for the nonstop Gulf crossing.
- Goldenrod rises in waves of gold across the prairies, marsh edges, and cheniers, critical fuel for migrating monarchs.
- Cooling, drier nights after the first fronts begin to clear the summer haze and sharpen the skies.
September 10–16
- Hawks stream down the coast in kettles — Broad-winged Hawks, Mississippi Kites, and the first Sharp-shinned and Cooper's.
- Muscadines and scuppernongs are at their fragrant peak, and the first sweet potatoes and satsumas begin to appear.
- Set out broccoli, cabbage, and cauliflower transplants and plant garlic and shallots in the warming fall soil.
September 17–23
- The southbound monarch migration builds, streaming along the coastal cheniers and Grand Isle ridges fueling on goldenrod and saltbush.
- The autumn equinox near September 22 balances day and night as Pegasus and Andromeda climb the eastern sky.
- Fall asters and swamp sunflower light the wet ditches, and saltbush whitens the marsh edges with swarming butterflies.
September 24–30
- A north wind can drop a fall fallout of warblers at Grand Isle and Peveto Woods as wintering teal pour into the marshes.
- Black gum leads the turn, blazing scarlet in the swamps, as beautyberry hangs heavy with violet fruit for the migrating birds.
- The fall tomatoes set out in late summer begin to fruit heavily as the nights cool — Louisiana's prized second crop.
Birds This Month
September is one of Louisiana's great migration months. Ruby-throated Hummingbirds reach their roaring peak, gardens and feeders mobbed as they fuel for the nonstop Gulf crossing — coastal yards can host dozens at once, and the first wintering Rufous Hummingbirds begin to appear. Southbound warblers stream through the coastal woods and cheniers — American Redstart, Northern Parula, Magnolia, Black-and-white, and Tennessee — and a north wind can drop a fall fallout at Grand Isle and Peveto Woods.
Hawks migrate down the coast — Broad-winged Hawks in kettles, Mississippi Kites, American Kestrels, and the first Sharp-shinned and Cooper's Hawks. Shorebirds still throng the ricelands and mudflats, and the marshes fill again as the first wintering Blue-winged and Green-winged Teal arrive — the vanguard of the great waterfowl return. Bobolinks and Dickcissels pass through the fields, Indigo and Painted Buntings stage along the coast, and Brown Pelicans, the state bird, work the shore. The Atchafalaya and lakes draw the first returning Northern Harriers.
What's Blooming
September gilds Louisiana with the great fall bloom of goldenrod, rising in waves of gold across the prairies, roadsides, marsh edges, and the coastal cheniers — the critical fuel for migrating monarchs and birds. With it come the fall asters, blazing star (gayfeather), ironweed, snow-on-the-prairie, false foxglove, and the late partridge pea and sunflowers, a riot of color on the Cajun Prairie remnants.
The wetlands still flame with cardinal flower and the great swamp mallow (rose mallow) hibiscus, and the climbing hempvine and groundsel bush (saltbush) begin to whiten the marsh and chenier edges, drawing clouds of butterflies. Gardens carry the heat-proof annuals — zinnias, pentas, lantana, cosmos — and the tropical plumeria, firebush, Mexican sunflower (tithonia), and cypress vine that fuel the hummingbirds. After heavy rains, rain lilies burst up overnight, and the first swamp sunflower begins to color the wet ditches.
Garden This Month
September is a major planting month in the Louisiana garden as the fall cool-season crops go in and the summer heat finally begins to ease. Set out transplants of broccoli, cabbage, cauliflower, Brussels sprouts, collards, and kale, and direct-sow the fall greens — mustard, turnips, spinach, lettuce, arugula, kale — along with carrots, beets, radishes, and green onions. Sow snap beans for a fall harvest, and plant garlic, shallots, and multiplying onions late in the month.
The fall tomatoes, peppers, and eggplant set out in late summer now begin to fruit heavily as the nights cool — Louisiana's prized second tomato crop. Keep watering as needed, mulch the new plantings, and shade tender seedlings from any lingering hot afternoons. Stay ahead of caterpillars on the young cole crops — cabbage loopers and armyworms surge now — and the persistent fall weeds. This is also a fine time to plant cool-season annuals, perennials, trees, and shrubs as the soil stays warm but the air cools, giving roots time to establish before spring.
Zone 8a (north Louisiana): the fall garden is in full swing before the earlier northern frost. Set out broccoli, cabbage, and cauliflower transplants, sow greens, carrots, beets, and turnips, and plant garlic and shallots late in the month.
Zone 9a (Acadiana & central prairie): prime fall planting. Set out cole-crop transplants and sow greens, lettuce, carrots, beets, radishes, and turnips, and harvest the fall tomatoes and peppers as they set in the cooling weather.
Zone 9b (lower delta & New Orleans): the long fall season begins. Plant broccoli, cabbage, greens, lettuce, and root crops, sow snap beans for an October harvest, and enjoy the fall tomato flush as the heat finally eases.
What's at the Farmers Market
September bridges summer and fall at Louisiana markets as the heat eases. Gulf shrimp from the fall white-shrimp season lands at the coastal docks, and the late summer produce mingles with the first fall crops at the Crescent City, Red Stick, and Lafayette markets.
The stalls carry okra, southern peas, eggplant, bell and hot peppers, the last summer squash, cucumbers, and the fall flush of tomatoes beginning. Muscadines and scuppernongs are at their fragrant peak, the last figs linger, and the first sweet potatoes of the fall harvest and early satsumas begin to appear. Local cane syrup, honey, eggs, pecans nearing, and cut flowers round out the markets. Choose muscadines fragrant and fully colored, handling gently. Pick sweet potatoes firm and unblemished and store them cool and dry but never refrigerated. Choose Gulf shrimp firm and translucent with a clean sea smell, keeping them on ice and using within a day or two.
Night Sky This Month
September's cooling Louisiana nights, especially after the first dry fronts, begin to clear the summer haze and return crisper skies. The darkest escapes from the river-city glow remain the open marshes of Sabine and Cameron Prairie NWRs, the Acadiana ricelands, the pinelands of Kisatchie National Forest, and the wide Atchafalaya. The Baton Rouge Astronomical Society, Pontchartrain Astronomy Society, and the LIGO Science Education Center near Livingston hold fall viewing programs.
The sky transitions from summer to autumn. The Summer Triangle of Vega, Deneb, and Altair still rides high overhead with the Milky Way through Cygnus, while the autumn constellations climb in the east — the Great Square of Pegasus, the chained princess Andromeda, and the W of Cassiopeia. On a truly dark night the Andromeda Galaxy shows as a faint smudge to the naked eye — the most distant object visible without aid. The autumn equinox near September 22 balances day and night. The printable Louisiana night-sky guide lists this year's planet positions, Moon phases, and dark-sky sites.
Butterflies & Pollinators
September is a peak butterfly month in Louisiana as the fall flights surge and the nectar-rich goldenrod opens. The cloudless sulphurs pour southward through the coastal parishes in their great fall flight, joined by abundant gulf fritillary, variegated fritillary, little yellow, sleepy orange, and the swallowtails — eastern tiger, giant, black, pipevine, and spicebush. The brushfoots throng the blooms: common buckeye, painted and American ladies, red admiral, and viceroy.
This is when the southbound monarch migration begins to build, the migratory super-generation streaming along the coastal cheniers and the Grand Isle ridges, fueling on goldenrod, saltbush, and lantana before the open-water crossing. The long-tailed and gray skippers and the great clouds of grass skippers swarm the fall nectar, and migrating fiery skippers mob the lantana. A garden of goldenrod, asters, lantana, and Mexican sunflower will be alive with butterflies all month — and a stand of native milkweed and fall nectar plants is vital fuel for the passing monarchs.
What to plant for them is in the Louisiana native plants guide
Trees This Month
September brings the first true hints of fall to Louisiana's trees, though full color is weeks away in this long-leaved state. The black gum (tupelo) leads, turning early scarlet and burgundy in the swamps and bottomlands, joined by the first reddening sweetgum, sumac, and Virginia creeper threading the trunks. The native fruits ripen for the migrating birds — black cherry, dogwood, beautyberry with its violet clusters, and the ripening persimmons.
In the swamps, the bald cypress, the state tree, and the water tupelo still hold green over the Atchafalaya but begin to show the first bronze cast that signals the coming turn, and the cypress cones ripen. The muscadines and scuppernongs hang ripe on the vines, and the live oaks drop the season's acorns along the coast and bayous. The northern pinelands stand dark green, and the longleaf savannas glow with the gold of the understory wildflowers beneath the open canopy as the cheniers gild with goldenrod and migrating birds.
The Louisiana native plants guide covers what grows with them
Weather & Daylight
Across Louisiana, a typical September day averages a high near 88°F and a low near 67°F, with about 4.5 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Heat begins to ease toward the upper 80s, nights cooling into the 60s, rain tapering to a lighter patter.
| Average high | 88°F |
|---|---|
| Average low | 67°F |
| Precipitation | 4.5 in |
| Sunrise (mid-month) | 6:51 CT |
| Sunset (mid-month) | 19:14 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 Louisiana's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Louisiana guides
The complete Louisiana birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: September in Maine · September in Maryland · September in Massachusetts