What's in Season in September: Where to See Fall foliage, Wildflowers in the US

What's in season in September?

September is fall foliage and wildflowers season at the places we track. Fall foliage is in its usual window at 27 places, the most in the week of Sep 22–30 (25), from Guanella Pass (Sep 1–Sep 30) to Kaiser Pass Road (Sep 25–Nov 30). Wildflowers: North Cascades (Feb 21–Sep 10), Lava Beds (Mar 1–Sep 30) and Grand Teton (May 1–Sep 30) and 2 more. Starting this month: aspen and cottonwood color at Lemhi Pass and aspens change in spearfish canyon at Spearfish Canyon.

Updated Sep 28. Sources: Bureau of Land Management, Lewis and Clark Backcountry Byway and Adventure Road guide ↗ (opens in a new tab), US Forest Service, Spearfish Canyon (Black Hills National Forest) ↗ (opens in a new tab)

Peaking in September

Each place's usual window, from its own sources

Fall foliage

27 places in September · 27 start this month

7Sep 1–7

14Sep 8–14

24Sep 15–21

25Sep 22–30

Colorado

Guanella PassRegional timing: Sep 1–Sep 30
Rocky MountainLocal timing: Sep 1–Oct 31
San Juan SkywaySep 11–Oct 20
Great Sand DunesSep 21–Oct 10
Maroon BellsSep 21–Sep 30

Maine

Katahdin Woods and WatersLocal timing: Sep 1–Oct 15

Washington

Mount RainierLocal timing: Sep 1–Sep 30
Washington PassSep 21–Oct 10

South Dakota

Spearfish CanyonLocal timing: Sep 1–Sep 30

New Mexico

Valles CalderaLocal timing: Sep 1–Nov 30

Wyoming

YellowstoneLocal timing: Sep 1–Oct 31

Nevada

Great BasinLocal timing: Sep 8–Sep 21

Utah

Bryce CanyonRegional timing: Sep 11–Oct 31
Capitol ReefRegional timing: Sep 11–Oct 31
Cedar BreaksRegional timing: Sep 11–Oct 31

Montana

GlacierLocal timing: Sep 11–Oct 20

Minnesota

VoyageursLocal timing: Sep 11–Sep 20
Chippewa National ForestSep 17–Sep 30
Mississippi River, Minneapolis–St. PaulSep 24–Oct 7

Vermont

Smugglers’ NotchStatewide timing: Sep 15–Oct 15
StoweStatewide timing: Sep 15–Oct 15
WoodstockStatewide timing: Sep 15–Oct 15

West Virginia

Canaan Valley RefugeSep 21–Sep 30

Michigan

Hiawatha National ForestLocal timing: Sep 21–Sep 30
Pictured RocksSep 24–Oct 10

Idaho

Lemhi PassLocal timing: Sep 21–Oct 31

California

Kaiser Pass RoadLocal timing: Sep 25–Nov 30

Wildflowers

5 places in September

5Sep 1–7

5Sep 8–14

4Sep 15–21

4Sep 22–30

Washington

North CascadesLocal timing: Feb 21–Sep 10

California

Lava BedsLocal timing: Mar 1–Sep 30
Lassen VolcanicLocal timing: May 21–Sep 30

Wyoming

Grand TetonLocal timing: May 1–Sep 30

District of Columbia

Kenilworth Aquatic GardensLocal timing: May 21–Sep 30

Also in September

From our places' year strips, each with its source

Blooms, blossoms and green-up

Still going at 16 places: wildflowers (8 places), wildflowers on the mogollon rim, late flowers: cardinal flower, rose mallow, then goldenrod and joe-pye-weed.

Fall color

Starting in September

Aspen and cottonwood color Lemhi Pass · Sep–Oct
Aspens change in Spearfish Canyon Spearfish Canyon · Sep
Best fall foliage Katahdin Woods and Waters · Sep–Oct
Best waterfowl and shorebird viewing Long Lake Refuge · Sep–Oct
Bog cranberries Chippewa National Forest, Minnesota · Sep–Oct
Color begins Hiawatha National Forest, Michigan · Sep
Cooler hikes, fewer biting insects Minnesota Valley Refuge · Sep–Nov
Fall color Canaan Valley Refuge · Sep

And 13 more.

Still going at 1 place: apple harvest.

Festivals and night skies

Starting in September

Astronomy Festival Great Basin · Sep
Battle anniversary (September 17) Antietam · Sep
Defenders' Day Baltimore (Fort McHenry) · Sep

Still going at 2 places: night sky tours at point supreme, ranger astronomy programs.

Out and about

Starting in September

Black bears busy before hibernation Great Dismal Swamp Refuge · Sep–Nov
Clearest days on the coast Point Reyes · Sep–Nov
Elk rut Valles Caldera · Sep–Oct
Fall migration and mild weather Occoquan Bay Refuge · Sep–Nov
Mac's Bend Road open to cars Missisquoi Refuge · Sep–Dec
Paddling on Cedar Creek Congaree National Park, South Carolina · Sep–Nov
Raptor migration along the Kittatinny Ridge Cherry Valley Refuge · Sep–Nov
Raptor migrations Rachel Carson Refuge · Sep

Still going at 110 places: busy season (3 places), cadillac summit road open, cadillac reservations.

Know before you go

Starting in September

Dutch Neck Road and Allee House area closed Bombay Hook · Sep–Feb
Fall archery hunt for deer and turkey Great Bay Refuge · Sep–Nov
Snake Road closed to cars Shawnee National Forest, Illinois · Sep–Oct

Still going at 6 places: caves closed for bats, off-trail areas closed for nesting, summer trail closures.

Sources (12)

Questions people ask

Where is fall foliage in September?

At the places we track: Guanella Pass, Colorado (regional timing Sep 1–Sep 30); Katahdin Woods and Waters, Maine (local timing Sep 1–Oct 15); Mount Rainier, Washington (local timing Sep 1–Sep 30); Rocky Mountain, Colorado (local timing Sep 1–Oct 31); Spearfish Canyon, South Dakota (local timing Sep 1–Sep 30); Valles Caldera, New Mexico (local timing Sep 1–Nov 30); and 21 more on this page.

Where are wildflowers in September?

At the places we track: North Cascades, Washington (local timing Feb 21–Sep 10); Lava Beds, California (local timing Mar 1–Sep 30); Grand Teton, Wyoming (local timing May 1–Sep 30); Kenilworth Aquatic Gardens, District of Columbia (local timing May 21–Sep 30); Lassen Volcanic, California (local timing May 21–Sep 30).

What festivals are in September?

Astronomy Festival at Great Basin (Sep); Battle anniversary (September 17) at Antietam (Sep); Defenders' Day at Baltimore (Fort McHenry) (Sep). Dates change each year; each place page links its source.

What should I know before a trip in September?

Bombay Hook: dutch neck road and allee house area closed; Great Bay Refuge: fall archery hunt for deer and turkey; Shawnee National Forest, Illinois: snake road closed to cars.