January is the heart of an Illinois winter — short gray days, hard freezes, and the prairie standing tan and bleached under wind-driven snow. The big rivers are the season's showpiece, drawing thousands of wintering bald eagles to the open water below the dams while feeders carry the rest of the state's bird life.
Week by week in January
January 1–7
- Bald eagles concentrate at the open water below the Mississippi and Illinois river dams, fishing the churning tailwaters in the season's classic Illinois winter spectacle.
- 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, and leave any snow banked over perennial beds as the best insulation an Illinois garden gets.
January 8–14
- Feeders are at their winter peak — northern cardinals blaze against the snow alongside chickadees, nuthatches, juncos, and tree sparrows.
- Orion dominates the southern sky, his belt pointing down to brilliant Sirius low in the southeast, with the cold, dry air making for crystal-clear viewing.
- Young white and red oaks hold their tan, papery leaves through winter in the trait called marcescence, rattling in the wind.
January 15–21
- On the Chicago lakefront, open Lake Michigan water draws gulls, goldeneye, and rafts of diving ducks, with the occasional snowy owl on the harbor walls.
- It's the safest window to prune oaks while fully dormant, avoiding the warm-season beetles that spread oak wilt; prune fruit trees on a mild day.
- Indoor winter markets sell the storage harvest — onions, potatoes, carrots, cabbage, and winter squash cured in fall and keeping well.
January 22–28
- Great horned owls begin nesting — the earliest in the state — and their deep hooting carries from woodlots and forest preserves on still nights.
- The Winter Hexagon of bright stars — Sirius, Procyon, Pollux, Capella, Aldebaran, and Rigel — sprawls across the long, dark January sky.
- Collinsville-area horseradish is at its sharp, pungent best after the deep freezes of midwinter.
Birds This Month
January is bald eagle season in Illinois, and it is spectacular. Wherever the Mississippi and Illinois rivers stay open below the lock-and-dam structures, bald eagles gather by the dozens to fish the churning tailwaters — the area around Lock and Dam 13 near Fulton, the Quad Cities, Starved Rock, and Pere Marquette on the lower Illinois are reliable spots for crowds of perched and soaring birds.
At the feeder, the cast is classic Midwest winter: the northern cardinal (the state bird) blazing against the snow, black-capped chickadees, white-breasted nuthatches, dark-eyed juncos, American tree sparrows, and downy and hairy woodpeckers. In irruption winters, watch for pine siskins and common redpolls pushed south from the north. On the Chicago lakefront, open water on Lake Michigan holds gulls, goldeneye, and rafts of diving ducks, with the occasional snowy owl on the harbor walls and beaches.
This month's tip: keep feeders full and clear of snow through cold snaps, when birds depend on them most, and add a heated birdbath for open water that seed alone will never provide.
What's Blooming
Nothing blooms outdoors in an Illinois January — the prairies and woodlands are frozen, and the earliest spring ephemerals are still two or three months away. The winter landscape offers structure and muted color instead: the deep-red stems of red-osier dogwood glow along wet ditches and stream edges, the persistent fruit of winterberry holly and highbush cranberry hangs bright against the snow, and the rattling, seed-laden heads of compass plant, coneflower, rattlesnake master, and the tall tan grasses of the prairie stand through the drifts at Midewin, Nachusa, and Goose Lake Prairie. Indoors, this is amaryllis and forced-paperwhite season — and the catalog-dreaming weeks when Illinois gardeners plan the beds they can't yet touch.
Garden This Month
January gardening in Illinois happens at the kitchen table. Beds are frozen statewide, so this is the planning month: order seeds, sketch next year's layout, and check stored dahlia tubers, bulbs, and tender roots for rot. It's also the safest window to prune oaks — pruning while they're fully dormant avoids the warm-season beetles that spread oak wilt — and to prune apples and other fruit trees on a mild, dry day.
Leave snow where it falls over perennial beds; it's the best insulation an Illinois garden gets, holding soil temperatures steady and shielding crowns from the brutal freeze-thaw cycles that kill more plants here than cold alone. Knock heavy, wet snow gently off evergreens and arborvitae to prevent splayed and broken branches, but leave the dry, fluffy snow in place.
Zone 5b (Chicago metro & northern Illinois): the garden is fully dormant under freeze and snow, and that snow is your best insulation — leave it banked over perennial crowns and against foundations. Order seeds early, and gently knock heavy wet snow off evergreen branches to prevent breakage.
Zone 6a (central Illinois): nothing to plant outdoors, but it's the right time to inventory seeds, sharpen and oil tools, and check that mulch is protecting marginal perennials and fall-planted bulbs through the deep cold.
Zone 7a (far southern Illinois / 'Little Egypt'): the state's mildest corner is still hard-frozen most of the month, but it is the safest window to prune dormant fruit trees and oaks on a mild day, and to plan an early spring garden that can start weeks ahead of the north.
What's at the Farmers Market
Illinois's outdoor farmers markets are closed for the season, but indoor winter markets keep the local harvest moving. Chicago's winter market editions and storage-crop stands across the state still sell the durable, fall-cured crops: storage onions, garlic, potatoes, carrots, beets, parsnips, cabbage, and winter squash that keep for months in a cool, dark cellar. Illinois apples are still eating well from cold storage.
Look also for jarred preserves and pickles, honey, eggs, and cold-season greens from the heated hoop houses a handful of growers run through winter. Collinsville horseradish — the region near St. Louis grows the bulk of the world's supply — is at its sharp, pungent best after the freezes of midwinter. Store roots in a cool, dark, humid spot and squash somewhere cool and dry, and they'll outlast the deepest cold.
Night Sky This Month
January gives Illinois its longest, darkest nights, and the cold, dry winter air is exceptionally clear — winter is prime stargazing if you can stand the temperatures. Orion dominates the southern sky, his belt pointing down to brilliant Sirius, the brightest star in the night, low in the southeast. Above and right of Orion glow the orange eye of Taurus (Aldebaran) and the tiny dipper of the Pleiades star cluster, with the bright twins of Gemini climbing in the east.
The Quadrantid meteor shower peaks in early January in a short, sharp burst best seen after midnight from a dark site. For the truly dark skies, head to the Shawnee National Forest in far southern Illinois, far from the immense glow of the Chicago metro that washes out the northern sky.
Exact planet positions and this year's specific meteor-peak dates shift from year to year — the printable Illinois night-sky guide lists the dates and visibility for your part of the state.
Butterflies & Pollinators
There are no butterflies on the wing in an Illinois January — it is far too cold across the whole state. The summer's butterflies are surviving the winter in hidden, dormant forms: the state's monarchs are thousands of miles south in the oyamel fir forests of central Mexico, while the species that stay here wait out the cold as eggs, chrysalises, or sheltering adults. Mourning cloaks and commas overwinter as adults tucked behind loose bark and in woodpiles, their natural antifreeze letting them survive deep freezes so they can fly on the first warm days of spring. The regal fritillary and other prairie specialists wait out the season as tiny first-stage caterpillars hidden in the thatch at Nachusa and Midewin. This is the month to plan a butterfly garden — native milkweed for monarchs and a succession of prairie nectar plants pay off when warmth returns.
What to plant for them is in the Illinois native plants guide
Trees This Month
Illinois's trees are fully dormant, and winter is when their architecture shows. The bare crowns of the great oaks — white oak (the state tree), bur oak, and red oak — dominate the woodlots and savanna groves, many young oaks still clutching last fall's tan, papery leaves in the trait called marcescence. The shaggy, peeling plates of shagbark hickory and the mottled white upper bark of sycamore along the rivers are easy winter ID marks.
In the far south, the bald cypress of the Cache River swamps stand leafless and gray, their knobby 'knees' poking from the frozen water — the only deciduous conifer of southern Illinois, having dropped their rusty needles back in November. Where conifers were planted, eastern white pine and eastern redcedar hold the only green in an otherwise gray-and-tan winter landscape.
The Illinois native plants guide covers what grows with them
Weather & Daylight
Across Illinois, a typical January day averages a high near 35°F and a low near 19°F, with about 2.3 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Sharp, dry cold settles in, days topping out near 35F while nights drop into the teens under crisp winter air.
| Average high | 35°F |
|---|---|
| Average low | 19°F |
| Precipitation | 2.3 in |
| Sunrise (mid-month) | 7:17 CT |
| Sunset (mid-month) | 16:53 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 Illinois's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Illinois guides
The complete Illinois birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: January in Indiana · January in Iowa · January in Kansas