What to look for in nature in Illinois this April

When do piping plovers return to Chicago's beaches in April?

• First plovers at Montrose Beach

  Late April or May; the Chicago Piping Plovers partnership lists Monty arriving in late April in 2022 and birds returning in May in 2023 and 2024 · Montrose Beach on the Chicago lakefront

  The partnership’s own account of recent seasons shows how much the first-bird date varies: Monty arrived in late April in 2022, and other birds returned in May in 2023 and 2024. A Chicago Sun-Times report counted two male plovers at Montrose on April 11, 2025, so an earlier arrival is possible. The first bird of 2027 could show up before or after the end of April, and the partnership posts sightings as they happen, which is the best way to find out whether anyone has landed yet.

• Giving plovers room

  April through July · Any nesting beach on Lake Michigan

  The federal profile advises visitors to stay well back from nesting shoreline between April and July. A bird that keeps leaving its scrape to avoid you is a bird that is not guarding its eggs, so watch from the posted line with binoculars, and photograph from a distance with a long lens rather than creeping closer.

• Night-herons at Lincoln Park Zoo

  March to August · Pritzker Family Children's Zoo, Lincoln Park, Chicago

  Lincoln Park Zoo says the largest black-crowned night-heron colony in Illinois roosts on its grounds from March to August, and that warbler season in Chicago starts in April. It is an easy, free place to see wild herons from the sidewalk.

Which migrant birds arrive in Illinois in April, and when do hummingbirds come back?

• Ruby-throated hummingbirds

  Mid-April to late April in most of the state; University of Illinois Extension says the arrival date varies from year to year · Gardens, woodland edges and feeders statewide

  IDNR says spring migrants begin showing up in Illinois around mid-April, and Extension describes mid-to-late April as the usual window, with 2026 an early year. Males come first. If you put out a feeder, Extension recommends a plain mix of four parts water and one part white sugar, and cleaning feeders every other day when possible. It says feeders should supplement, not replace, the flowers and insects that hummingbirds need. You can report your first hummingbird to Journey North, which maps the northward wave.

• Swallows, martins and house wrens

  Barn swallows arrive in early April; purple martin males in late March to early April; house wrens in April · Farms, open water, bridges, martin houses and backyard boxes

  IDNR calls the barn swallow the most common swallow in the state and says early April is the usual arrival time. It calls the purple martin a common migrant and summer resident whose males come first, with egg-laying running from mid-April on, and says most martins now nest in boxes people provide. The Chicago Botanic Garden notes that its martins return year after year to the same housing. House wrens move into any small cavity, so a nest box hung in April may be claimed within days.

• Wood thrushes and orioles

  Wood thrushes in late April; Baltimore orioles in southern Illinois by mid-to-late April and statewide by early May · Bottomland forests and wooded ravines (thrush); yards, edges and tall trees (orioles)

  The wood thrush's flutelike dawn and dusk song is one of the first sounds of Illinois bottomland woods in late April, according to IDNR. The Outdoor Illinois Journal reports that Baltimore orioles reach southern Illinois by mid-to-late April and spread north by early May, and that both Baltimore and orchard orioles will visit hummingbird feeders and take orange halves and grape jelly.

• Prairie arrivals at Midewin and Nachusa

  April · Midewin National Tallgrass Prairie near Wilmington; Nachusa Grasslands near Dixon

  The Nature Conservancy's Illinois seasonal guide lists ruby-crowned kinglets, blue-winged teal, loggerhead shrikes and upland sandpipers among the April returnees at Midewin, and eastern bluebirds, turkey vultures and sandhill cranes holding territory at Nachusa. The Forest Service describes Midewin as one of the Midwest's important sites for grassland birds, including dickcissels, bobolinks and Henslow's and grasshopper sparrows.

Where do Virginia bluebells and other Illinois spring wildflowers peak in April?

• Virginia bluebells at Starved Rock

  Mid-to-late April; bluebells were in bloom on April 13 in 2026 and at peak on April 22 in 2025 · Illinois Canyon trailhead, Starved Rock State Park, near Oglesby

  Shaw Local photographers found tens of thousands of Virginia bluebells carpeting the Illinois Canyon trailhead on April 22, 2025, with cutleaf toothwort, spring beauty, bristly buttercup, false rue anemone, blue violet and redbud in bloom nearby. Their 2026 photos, taken on April 13, already showed bluebells in bloom, so the timing clearly shifts from year to year. Check the park's current reports before you drive, and stay on the trail so the carpet survives.

• Bloodroot, Dutchman's breeches and spring beauty

  Over the course of April · Allerton Park (Piatt County), Busey Woods in the Champaign-Urbana area, Forest Glen Preserve (Vermilion County) and similar rich woods

  The Illinois Public Media piece names these three as the stars of April and points to Allerton Park, Busey Woods, Forest Glen and the Middle Fork of the Vermilion River natural areas. Bloodroot's white flowers last only a day, so a single patch can look different from one morning to the next.

• Redbud and the first trees

  April into May in northern Illinois · Woodland edges, yards and the shores of lakes and ponds

  University of Illinois Extension calls the eastern redbud one of the earliest trees to bloom, with flowers appearing before the leaves, and says its blossoms are an early food source for bumble bees and carpenter bees. At The Morton Arboretum in Lisle, staff describe April as the mid-season for bloom: East Woods wildflowers, the daffodils in Daffodil Glade and redbuds along Lake Marmo, with crabapples and magnolias usually later, in May. Lincoln Park Zoo adds that bud break arrives on Chicago's trees in April.

• Arbor Day

  The last Friday in April, which is April 30, 2027 · Statewide

  Illinois observes Arbor Day on the last Friday in April under state law (5 ILCS 490/10), the same Friday as the national observance, according to a Congressional Research Service fact sheet. In 2027 that is April 30. It is a good day to plant a native redbud, serviceberry or oak, and to put up a nest box.

Where can you see baby bison and booming prairie-chickens in April?

• Bison calves at Nachusa and Midewin

  Calves are born in April, May and June · Nachusa Grasslands near Dixon (the herd roams about 1,500 acres); Midewin National Tallgrass Prairie near Wilmington (southeast bison pasture)

  The Nature Conservancy says the Nachusa herd numbers about 100 animals, and that newborn calves weigh about 50 pounds and can stay with the herd within hours. The Friends of Nachusa Grasslands list roadside viewing from the visitor center overlook, Lowden Road, Naylor Road and Stone Barn Road, and say the animals move unpredictably, so sightings are not guaranteed. Cows defend calves hard, and bison can run faster than 30 miles per hour. The Conservancy asks for at least 100 yards of distance and the Friends group says 100 feet, so use the larger number. Nobody may walk into the fenced bison units, and the Forest Service points visitors to the southeast bison pasture at Midewin.

• Greater prairie-chickens at Prairie Ridge

  Booming season is April through early June; females visit the booming grounds in highest numbers close to April 10, according to a 2022 IDNR account · Prairie Ridge State Natural Area, Jasper and Marion counties

  The state agency classes the greater prairie-chicken as endangered and reports that the species hangs on only on managed preserves in these two counties; the male's hollow boom has been compared to a breath across a glass bottle. The 2022 account counted about 52 males in Jasper County and 18 in Marion County, up from a low of 12 males in Jasper County in 2014 after birds were brought in from elsewhere in 2014, 2016 and 2017. We found no public 2027 viewing program posted, so inquire first. Never walk onto a booming ground. The Illinois Audubon Society owns a 160-acre preserve within the natural area and bought another 80 acres in 2025, so contact the Society or IDNR for any visits they may offer in 2027.

Which frogs and toads are calling in Illinois in April?

• American toad and Fowler's toad

  Spring, with Fowler's toads calling at urban ponds in April · Gardens, lawns, ponds and ditches; American toads everywhere in Illinois except the southeastern quarter

  IDNR describes the American toad's call as a high, musical trill, and says a female lays between 2,000 and 20,000 eggs in long strings on the bottom of shallow water, with tadpoles changing into toads by early June. Lincoln Park Zoo says Fowler's toads begin calling at city ponds in April. Toads are often the first amphibian a child finds at a porch light.

• Northern leopard frog

  Mid-March through May · Ponds, lakes, sloughs and flooded fields in the northern half of Illinois

  IDNR gives mid-March through May as the breeding period and says the call can be imitated by rubbing a thumb across an inflated balloon. In summer these frogs wander into prairies and field edges.

• Cope's gray treefrog

  Late April into August · Woodlands next to water, statewide

  Late April is when the first gray treefrogs join the chorus. IDNR describes the call as a high buzzing trill that sounds a little like a red-bellied woodpecker, and says the frogs shelter in dead trees, under bark and in rotting logs.

• Snake Road stays closed

  Through May 15 · Forest Service Road 345, LaRue-Pine Hills, Shawnee National Forest

  The Forest Service keeps this road closed to vehicles from March 15 through May 15 so that snakes and amphibians can cross from the bluffs to LaRue Swamp. Foot traffic is allowed, collecting and handling are not, and volunteer Snake Sentinels help visitors with identification. The agency says the area holds about two-thirds of the state's amphibians and 59 percent of its reptiles.

When do morel mushrooms and spring trout season come to Illinois?

• Morel mushrooms

  Black morels can appear as early as mid-March in southern Illinois and the common (yellow) morel in early April, according to IDNR; University of Illinois Extension says they spread across the state over the following weeks, depending on spring weather · Forested areas; Giant City State Park and the Shawnee National Forest region are well-known southern destinations

  IDNR’s Kids for Conservation archive (2015) says Illinois permits morel hunting in state parks for personal use only, with no sales, and not in nature preserves. At some IDNR sites that offer spring turkey hunting, mushroom collecting is held back until the afternoon, so ask the site about its current rule. The same page says a mushroom you cannot positively identify should not be eaten, that morels need thorough cooking and that alcohol should be avoided with them. Allerton Park's natural areas manager told Extension that the damage comes from human disturbance, not the picking, and that Allerton's rule is to stay on trails. Call the site before you go, because rules vary.

• Spring trout season

  Usually catch-and-release at select sites in late March, then the regular season in early April; IDNR has not posted 2027 dates yet · Stocked ponds, lakes and streams statewide; see the IDNR iFish site for the list

  Illinois Department of Natural Resources says an additional 80,000 trout are stocked for the spring season, which begins in April, and that anglers need a fishing license and an inland trout stamp unless exempt. Before the opener, only designated catch-and-release sites are open, and fishing elsewhere is not allowed. Dates change from year to year, so check the IDNR iFish site in March 2027; it carries the list of trout sites, fishing regulations and upcoming events.

• White bass below Starved Rock Dam

  Spring; one 2010 magazine account puts the white bass feeding near mid-April · Illinois River below the dam at Starved Rock State Park, down to Peru

  Writer Ted Peck wrote in Game and Fish magazine that white bass feed heavily around mid-April below Starved Rock Dam, and that sauger and walleye also run in the tailwater in late March or April. This is one angler's account from 2010 rather than an agency forecast, so use the timing only as a loose guide and ask a local bait shop or IDNR fisheries staff.

What is April weather like in Illinois, and when does severe weather start?

• Severe weather season

  April through September; the first big outbreaks can come in April · Statewide; National Weather Service forecast offices including Chicago and Central Illinois (Lincoln)

  The National Weather Service in Chicago defines its severe weather season as April through September. A reminder of what April can do came on April 9, 2015, when 11 tornadoes touched down in Illinois, including an EF4 that ran 30.2 miles through Lee, Ogle and DeKalb counties near Fairdale and Rochelle, killing 2 people and injuring 22. The Central Illinois forecast office advises having a shelter place on the lowest floor of the building in an interior room or basement, receiving alerts through NOAA Weather Radio, phone alerts, TV, radio or the NWS apps, and not counting on outdoor sirens, which are not designed to be heard indoors.

When is the last spring freeze in Illinois?

How much daylight does Illinois gain in April?

What can you see in the Illinois night sky in April 2027?

• The Pink Moon

  Full at 5:27 p.m. CDT on Tuesday, April 20; the best evening is April 20 · Rising in the east about 7:50 p.m. in Chicago

  Sea and Sky says the Pink Moon takes its name from spring wildflowers. The full moon peaks before the moon rises, so watch the moon come up on the evening of April 20, and check again the evening before and after.

• Lyrid meteors in a bright-moon year

  Active about April 14 to 30; the peak is predicted for about 8:41 p.m. CDT on Thursday, April 22 · Look low in the east-northeast early in the evening, in the direction of Lyra

  The Moon is nearly full (about 95 percent lit) three days after the Pink Moon and rises around 10 p.m. in Chicago on April 22. Only the early evening is moonless, when the radiant is still low. Sea and Sky rates the Lyrids an average shower, usually near 20 meteors an hour at the peak, but notes the nearly full moon will drown out fainter streaks; the likely count is only a few per hour. SeaSky adds that brighter meteors may still show after midnight from a dark site. Short, unpredictable outbursts have caught observers off guard in other years.

• Jupiter, the Moon and Mars in the evening

  All month; the Moon passes Jupiter on the evenings of April 14 and 15, and is near Mars on the evening of April 15 · High in the south after dark

  Jupiter is a bright, steady point in the evening sky all month and sets in the early hours of the morning. A gibbous moon, roughly two-thirds lit, comes within a degree of Jupiter during the daytime on April 15, so the nights before and after show the pair at their closest after dark. On the evening of April 15 the Moon also sits a few degrees from Mars, a modest orange star of about magnitude 0.

• Venus before dawn

  All month; the Moon, a thin 9 percent crescent, is near Venus on the mornings of April 3 and 4 · Low in the east before sunrise

  Brilliant Venus clears the horizon about 75 minutes before sunrise as April opens (our estimate for the central United States), and that lead shrinks to near an hour by early May. Because Saturn sits in the Sun's direction on April 7, it stays hidden until it starts to show in morning twilight in early May.

What can Illinois families do outside in April?

Safety notes for April in Illinois