What to look for in nature in Illinois this October

When do the leaves peak in Illinois, north to south?

• Where to go in the north and center

  Second and third weeks of October in the north; late October in the center · Galena; Starved Rock and Matthiessen state parks; Allerton Park near Monticello; Lake Decatur

  The report sends northern travelers to the Galena hills and to Starved Rock, where the canyons along the Illinois River hold maples and oaks. Starved Rock Lodge, inside the park, lists guided hikes at 10 a.m. and Matthiessen hikes at 9 a.m. on October 3 and 4, and fall color trolley tours with lunch on October 3 and 6; check its calendar for later dates. In the center, the picks are Allerton Park on the Sangamon and the woods around Lake Decatur. In farm country, drive the river bluffs, where the big trees are.

• The Shawnee and the Cache River

  Last week of October; bald cypress into late November · Garden of the Gods, Giant City State Park, Cache River State Natural Area

  At Garden of the Gods, near Harrisburg, the quarter-mile Observation Trail winds among sandstone formations named Camel Rock and Devil’s Smokestack above oak and hickory hills. Farther south the Cache River swamps turn last: bald cypress, some over 1,000 years old with buttresses more than 40 feet around, go copper, and the Wildflower Center puts that terra-cotta color at its best “around Thanksgiving.”

When is the Snake Road migration in the Shawnee National Forest?

• What you might see

  Through October 30; warm afternoons are best · Forest Road 345, off Illinois Route 3 near Muddy Levee Road, about 14 miles south of Murphysboro

  The Forest Service counts 35 snake species here, about 59 percent of the reptiles known from Illinois, and 23 amphibians, about two-thirds of the state’s. Its list runs from western cottonmouths and copperheads to rat snakes, kingsnakes, hognose snakes, rough green snakes, marbled salamanders and box turtles. Herpetologists say ground temperature sets the migration moving, so a sunny afternoon after a cool night is a good bet; in a cold snap you may see nothing.

• How to visit

  Daylight; allow two to four hours round trip · Small parking area for about 15 cars

  The walk is flat, 1 to 2 hours each way. Stay on the gravel, give every snake room and never pick one up; copperheads and cottonmouths live here, and handling or collecting any animal is against federal and state law. LaRue-Pine Hills/Otter Pond became the nation’s 250th Research Natural Area in 1991, holds more than 1,350 species, and is one of only two places in Illinois where shortleaf pine grows wild. The nearest hospital is in Murphysboro.

• Snake Sentinels

  During the closures · Snake Road

  The Forest Service trains volunteers, called Snake Sentinels, to count snakes, visitors and cars on the road. If you walk it often, ask the Shawnee’s Mississippi Bluffs Ranger District about the training; the counts help the Forest Service see how the closure is working.

When do the ducks build up on the Illinois River?

• The 2026 story so far: a flood, then a slow start

  September surveys · Illinois and central Mississippi rivers

  The first 2026 flight, on September 3, was “a Tale of Two Rivers”: the Illinois was still recovering from a mid-summer flood that drowned the moist-soil plants ducks eat, while the Mississippi looked better. By September 17 pintails, green-winged teal and shovelers were arriving, but blue-winged teal ran 9 percent below the 10-year average on the Illinois and 53 percent below on the Mississippi, and the mudflats left by falling water were sprouting late. “Time isn’t on our side,” the survey noted. A thin food crop can mean birds pass through rather than linger.

• What late October usually looks like

  Building through October; peak usually in November · Emiquon, Chautauqua, Rice Lake, Senachwine Lake

  For comparison, the late-October flight in 2025 found 146,925 ducks in the Illinois River valley, 29 percent under the long-term average, most of them on freshly flooded moist-soil units. Green-winged teal were a little above average, almost half of that surplus on Chautauqua National Wildlife Refuge near Havana, while mallards were well under. The valley’s biggest numbers usually come later.

• Emiquon and Chautauqua

  Ducks from October to late November; refuge sanctuary closure from October 16 · Near Havana and Lewistown, about an hour southwest of Peoria

  The Fish and Wildlife Service says its Emiquon refuge averages a one-day peak of about 71,450 ducks of 28 waterfowl species, usually in November. Parts of the refuge close as a waterfowl sanctuary from October 16 to January 31, but The Nature Conservancy’s Emiquon Preserve next door keeps its boardwalk and spotting scopes open sunrise to sunset. White pelicans, logged on the survey’s first flight, still use these lakes early in the fall. Chautauqua, a sanctuary since 1936, is a Ramsar Wetland of International Importance.

What is moving along the Chicago lakefront in October?

• The Illinois Beach hawk watch

  August 25 to November 25; sharp-shins at mid-October, merlins later · Illinois Beach State Park, Zion, from the pavilion east of Sand Pond

  Volunteers have counted raptors here since 2000, for at least four hours a day when weather allows, and visitors are welcome. Seasons average about 1,400 red-tailed hawks, 1,140 sharp-shinned hawks, 1,110 broad-wings (mostly in September) and some 400 merlins, plus ospreys, harriers, Cooper’s hawks, kestrels, peregrines and the odd golden eagle. Sharp-shins crest around mid-October and merlins late in the month.

• Sparrows and kinglets

  All month · Montrose Point Bird Sanctuary, Jackson Park’s Wooded Island, North Pond, Big Marsh

  White-throated sparrows are the signature bird of a Chicago October, under every shrub in every park, with kinglets, hermit thrushes, juncos and the last warblers on the same edges. Montrose Point is the famous spot; Wooded Island in Jackson Park, North Pond in Lincoln Park and Big Marsh on the Southeast Side all hold migrants on a good morning.

• Lights Out Chicago

  August 15 to November 15 · Downtown and lakefront buildings; any home with lit windows

  Night migrants steer by the stars and get trapped circling bright buildings until they hit glass or drop. Lights Out Chicago, running since 2000 and the first coordinated program of its kind, asks tall buildings to shut decorative lights after 11 p.m. and everyone to draw blinds or switch off lights overnight. Chicago Bird Collision Monitors, whose volunteers pick up stunned birds downtown at dawn, find white-throated sparrows more than any other species; in one October night in 2023, nearly 1,000 birds died against McCormick Place. Put a stunned bird in a closed paper bag or box and take it to a rehabilitator such as Willowbrook Wildlife Center.

• Sandhill cranes over the city

  First flocks in the second half of October; the big days come in November · Overhead across northeastern Illinois, headed southeast

  Thousands of eastern sandhill cranes stop at Jasper-Pulaski Fish and Wildlife Area in northwest Indiana from mid-October through mid-December, peaking in late November or early December; Indiana DNR counted 16,400 there on December 2 last year. Many cross the Chicago area on the way, in long wavering lines, with a rolling, trumpeting call you hear before you see them. October flocks are small, so write down the date of the first one.

• Salmon in the harbors

  In the harbors from mid-September; snagging season October 1 to December 31 · Jackson, Diversey and Waukegan harbors; Lincoln Park Lagoon; the Winnetka power plant discharge

  Each May the Jake Wolf Memorial Fish Hatchery stocks chinook and coho salmon in Jackson, Diversey and Waukegan harbors. They return there as adults, and from mid-September the harbors fill with fish looking for a river that is not there. Snagging is legal from October 1 through December 31 at four named places, including Lincoln Park Lagoon south of Fullerton Avenue and Waukegan’s North Harbor basin, five fish a day. The lake is cooling fast: NOAA Great Lakes lab satellite averages for 1995–2025 put Lake Michigan near 62 °F on October 1 and 52 °F on Halloween.

When is the first frost and freeze in Illinois?

How much daylight does Illinois lose in October?

What is October weather like in Illinois, and what could El Niño mean for the winter?

What is in the Illinois night sky this October?

• The moon covers Jupiter

  Tuesday, October 6, about 3:20 to 4:20 a.m. CDT · Low in the east; the moon 7 to 20 degrees up

  The waning crescent rises at about 2:18 a.m. in Chicago and 2:31 in Springfield with Jupiter about one moon-width off its bright edge. According to IOTA, the occultation timers’ association, the planet disappears at the moon’s sunlit edge at 3:22 a.m. in Chicago (3:21 at Kankakee, 3:18 at Belleville, near St. Louis) and returns from the dark edge at 4:17 in Chicago and 4:16 at Belleville, with the sun well down both times. The moon is only about 10 degrees up in Chicago at the start and lower downstate, so find an open eastern horizon: a lakefront beach, a hilltop, a harvested field.

• The Hunter’s Moon

  Evenings of Sunday, October 25 and Monday, October 26 · Rising in the east around sunset

  The moon is exactly full at 11:12 p.m. CDT on the 25th. In Chicago it rises at 5:19 p.m. that evening, 35 minutes before the 5:54 sunset, and at 5:51 p.m. the next evening, about as the sun goes down; in Springfield the times are 5:32 and 6:05 p.m. It is not a supermoon this year.

• Orionids

  Active October 2 to November 7; best on the mornings of October 21 and 22 · Anywhere dark, facing south and east

  Fast meteors from the dust of Halley’s Comet, often leaving trails. The peak is broad; the obstacle is a bright gibbous moon. It sets at 2:02 a.m. in Chicago on the morning of the 21st, and at 3:09 a.m. (3:19 in Springfield and Carbondale) on the 22nd. From then until dawn grays the sky, around 6, is the window; ten to twenty an hour from a dark site is a fair year.

• Draconids

  Evening of Thursday, October 8 · Look high in the north after dusk

  An early-evening shower, so it suits a school night, and the moon stays out of the way until the small hours before dawn. Rates are usually low and hard to predict; give it half an hour and count anything you see as a bonus.

• Planets: Saturn all night, Jupiter and Mars at dawn

  Saturn at opposition Sunday, October 4; Mars at the Beehive October 11 · Saturn east at dusk; Jupiter and Mars east before sunrise

  Opposition on the 4th puts Saturn up from dusk to dawn, a steady yellowish light in an empty stretch of sky; the moon pairs with it on October 23–24. Venus can be caught very low in the west after sunset only at the start of the month, before it drops into the glare and reaches inferior conjunction on October 23. At dawn Jupiter outshines everything in the east, and on October 11 Mars passes the Beehive cluster, a fine pairing in binoculars.

What is ripening on the prairies and in the southern woods?

• Big bluestem and the bison prairies

  Seed ripe in October and November · Nachusa Grasslands near Franklin Grove; Midewin National Tallgrass Prairie near Wilmington

  Big bluestem, four to eight feet tall, turns a maroon-tan in fall and ripens its three-pronged “turkey foot” seed heads in October and November, when restoration volunteers go out to strip seed by hand. Two Illinois prairies carry bison again. The Nature Conservancy brought 30 to Nachusa Grasslands in October 2014; the herd now numbers about 120–130 in summer on 1,500 acres. The Forest Service brought bison to Midewin, on the old Joliet arsenal, in 2015, and its Iron Bridge Trailhead information station, with loaner binoculars, is staffed weekends 10:30 a.m. to 4 p.m. through October. Neither place can promise a sighting.

• Persimmons and pawpaws

  Persimmons late September into November; pawpaws early fall · Woods edges and old fields, mostly central and southern Illinois; pawpaws in river bottoms

  Wild persimmons turn orange from late September into November, but an unripe one is full of tannin and puckers the whole mouth; the Wildflower Center says they are not edible until they have had frost or steady cold, so wait until they are soft, wrinkled and on the ground. Pawpaws ripen in fall and often drop before they are fully ripe, finishing on the kitchen counter; they are ready when the skin browns. Eat only fruit you can identify.

• Hedge apples

  Dropping from late fall into winter · Old fence rows across the prairie counties

  The green, brain-wrinkled balls, four to six inches across, come from Osage orange, a southern tree settlers planted as living fence before barbed wire; its thorny rows still mark old field lines across central Illinois. The Morton Arboretum notes the fruit drops from female trees in late fall and on through winter.

What are Illinois deer, bats and other animals doing in October?

• Deer: the rut begins

  From October; peak mid-November · Statewide, and on every rural road at dusk

  IDNR says white-tailed deer breed from October through January, peaking in mid-November. This month bucks rub saplings bare and paw out scrapes, patches of bare ground marked with urine, along woods edges. The dusk and dawn watch plate is made for a deer logged with the time and the light.

• Bats looking for a winter home

  Fall · Attics, garages and chimneys

  IDNR’s Wildlife Illinois notes that in fall bats may move into houses and other buildings to hibernate. If one gets into the living space, close off the room, open a window and let it leave on its own; never handle a bat bare-handed, and call the local health department if anyone may have been bitten. Bat Week, October 24–31, is a good time to learn which Illinois bats hibernate in caves and which fly south.

• The last crickets

  Until the first hard freeze · Any warm evening outdoors

  Snowy tree crickets slow as the evenings cool. The number of chirps in 14 seconds, plus 40, gives a fair guess at the temperature in °F; the cricket thermometer plate holds those counts, and the first silent night deserves a line too.

What can Illinois families do outdoors in October?

Safety notes for October in Illinois