April is the great green awakening in Wisconsin — the spring ephemerals carpet the Driftless woods, the marshes ring with returning birds, and the southern counties green up while the north still wears patches of snow. The migration and the wildflower bloom both accelerate by the week.
Week by week in April
April 2–8
- Eastern phoebes, tree swallows, and yellow-rumped warblers lead the songbird wave as the spring migration accelerates by the day.
- The spring ephemeral bloom begins in the Driftless woods — bloodroot, spring beauty, and Dutchman's breeches open before the canopy closes.
- As soon as the soil can be worked, direct-sow peas, spinach, lettuce, and radishes, and plant onion sets and potatoes in the south.
April 9–15
- Before dawn at the Buena Vista grasslands, male greater prairie-chickens boom and dance on their leks — a great Midwestern spectacle.
- Trout lily, rue anemone, and cut-leaved toothwort carpet the rich woods, joining marsh marigold glowing gold in the seeps.
- Serviceberry lights the woodland edges with white, one of the earliest tree blooms, as aspens haze the hillsides green.
April 16–22
- Sandhill cranes and trumpeter swans are displaying and nesting at Horicon and Crex Meadows as the first warblers begin to filter through.
- The Lyrid meteor shower peaks around April 22, its fast meteors radiating near bright Vega, best seen after midnight from a dark site.
- Cabbage whites and tiny spring azures appear in gardens and along woodland edges as warmth becomes more reliable.
April 23–29
- The first large-flowered trillium open in the warmest woods, and Virginia bluebells color the Driftless river bottoms blue.
- The warbler wave builds through the last week of April as scarlet tanagers and rose-breasted grosbeaks begin to arrive from the south.
- Set out cool-season transplants of cabbage, broccoli, and kale, but keep tomatoes indoors — frost risk runs into late May, especially up north.
Birds This Month
April is one of Wisconsin's two best birding months, with new arrivals every day. Eastern phoebes, tree swallows, chipping sparrows, and yellow-rumped warblers lead the songbird wave, while ruby-crowned and golden-crowned kinglets, hermit thrushes, and fox sparrows move through the woods. Sandhill cranes are now displaying and nesting across Horicon Marsh and the central marshes, and at Crex Meadows in the northwest the first trumpeter swans and waterfowl crowd the flowages.
The marquee April event is the dawn display of the greater prairie-chicken on the Buena Vista grasslands near Wisconsin Rapids, where males boom and dance on their leks at first light. Waterfowl migration peaks early in the month, woodcock peent and sky-dance at dusk over wet thickets, and the first eastern meadowlarks, field sparrows, and brown thrashers sing from old fields.
This month's tip: get to a prairie-chicken blind at Buena Vista before dawn (reservations required) for one of the Midwest's great wildlife spectacles, and watch warbler numbers build through the last week of the month.
What's Blooming
April is the peak of Wisconsin's spring ephemeral bloom, and the rich woods of the Driftless Area and southern counties are at their most beautiful. The forest floor fills with white before the canopy closes: bloodroot, spring beauty, Dutchman's breeches, cut-leaved toothwort, rue anemone, and the nodding yellow bells of trout lily, with hepatica and wild ginger among the early leaves. In wet woods and seeps, marsh marigold glows gold, and the first large-flowered trillium open in the warmest spots by late month.
This is a fleeting display — the ephemerals bloom and set seed in the brief window before the trees leaf out and shade the floor. Oak savanna and prairie remnants green up more slowly, while in gardens daffodils, scilla, and tulips bloom across the south. The bloom runs roughly two to three weeks later in the far north.
Garden This Month
April is when Wisconsin gardens truly come alive. As soon as the soil can be worked without clumping, direct-sow the cool-season crops — peas, spinach, lettuce, kale, radishes, carrots, and beets — and plant onion sets, potatoes, and asparagus crowns. Cool-season transplants of cabbage, broccoli, and cauliflower can go out under cover in the south. Hold all tender, warm-season crops (tomatoes, peppers, beans, squash) indoors; the average last frost ranges from late April in the far southeast to late May or even early June in the north.
Finish bed cleanup, divide and replant overcrowded perennials as they emerge, and top-dress beds with compost. Harden off indoor-started seedlings by setting them outside for lengthening stretches on mild days. April's weather swings wildly — a 70-degree afternoon can be followed by a hard freeze, so keep row cover handy and don't be lured into planting tender crops early.
Zone 4a (north-central & northeast): the ground is finally workable late in the month — direct-sow peas, spinach, lettuce, and radishes, and plant onion sets and potatoes. Keep frost protection ready; hard freezes are still common into May.
Zone 4b (central Wisconsin): sow cold-hardy greens, peas, carrots, and beets outdoors, set out onion and brassica transplants, and harden off seedlings on mild days. Don't plant tomatoes yet — frost risk runs well into late May.
Zone 5b (Milwaukee & southern lakeshore): the lake-warmed southeast is well ahead — plant potatoes, onions, peas, and all the cool-season greens, and set out cabbage, broccoli, and kale transplants. Watch the forecast before any tender planting.
What's at the Farmers Market
April markets begin the transition from storage to the first fresh greens of spring. Outdoor markets are reopening across the state by late month, and the season's earliest field harvests appear: asparagus in the warmest southern spots, overwintered spinach, rhubarb, green onions, radishes, and tender greenhouse-grown lettuces and microgreens. The last of the maple syrup run is bottled and abundant.
Storage crops fade to a few remaining onions, potatoes, and squash, and bedding plants, herb starts, and vegetable seedlings begin to dominate the stalls for home gardeners. Wisconsin cheese, eggs, and honey are constants. Choose asparagus with tight, firm tips and rhubarb with crisp, deeply colored stalks, and refrigerate both promptly — the first fresh produce of the year is at its best within a day or two of picking.
Night Sky This Month
April's milder evenings make for comfortable stargazing as the spring sky settles in. Leo rides high in the south, and the curving handle of the Big Dipper arcs down to brilliant orange Arcturus in Boötes — the old skywatcher's trick of "arc to Arcturus." Continue the curve to reach blue-white Spica in Virgo. The winter stars set earlier in the west each night now.
The Lyrid meteor shower peaks around April 22, a modest but reliable shower whose fast meteors radiate from near the bright star Vega, best seen after midnight from a dark site. This is a fine season for galaxy hunting in the dark skies of the northwoods, where the realm of distant galaxies in Leo and Virgo lies high overhead. Aurora remains possible on geomagnetically active nights along the northern horizon.
For exact planet positions and this year's Lyrid peak timing, consult the printable Wisconsin night-sky guide for your part of the state.
Butterflies & Pollinators
April brings a real, if modest, butterfly season to Wisconsin. The overwintering adults — mourning cloaks, eastern commas, and question marks — are now active on most warm days, and they're joined by the first fresh spring species. Cabbage whites appear in gardens and weedy lots, small white spring azures flutter low along woodland edges, and the tiny eastern tailed-blues work sunny clearings. In the rich Driftless woods, the spring ephemeral bloom draws nectaring butterflies, and the gorgeous olympia marble and elfins fly in dry oak barrens. Migratory red admirals and painted ladies begin arriving from the south, sometimes in waves during big flight years. Wisconsin's signature endangered butterfly, the Karner blue, is still weeks from its first flight, waiting on the wild lupine that is only now sending up its leaves in the central sand-county barrens.
What to plant for them is in the Wisconsin native plants guide
Trees This Month
April leaf-out sweeps north across Wisconsin. The silver and red maples finish flowering and set their reddish samaras, aspens and willows haze the hillsides with the first green, and the sugar maples and basswoods begin unfurling. The flowering of serviceberry (juneberry) lights the woodland edges with white, one of the earliest tree blooms, soon followed by wild plum and cherry.
The oaks — bur, white, and red — leaf out late, holding their gray branches bare while the rest of the forest greens. In the bogs and tamarack swamps, the tamaracks remain the very last to break bud. Across the north, leaf-out runs roughly two to three weeks behind the southern counties, so the green wave is still climbing the bluffs and ridges as April closes.
The Wisconsin native plants guide covers what grows with them
Weather & Daylight
Across Wisconsin, a typical April day averages a high near 54°F and a low near 32°F, with about 3.2 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
A true transition month, mild 54F afternoons meet chilly 32F mornings, and frequent showers keep everything soggy and green.
| Average high | 54°F |
|---|---|
| Average low | 32°F |
| Precipitation | 3.2 in |
| Sunrise (mid-month) | 6:16 CT |
| Sunset (mid-month) | 19:41 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 Wisconsin's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Wisconsin guides
The complete Wisconsin birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: April in Wyoming · April in Alabama · April in Arizona