May is the peak of the Minnesota spring — the warbler migration crests, the woods fill with trillium and wild geranium, and the last frost finally releases the gardens. It's the most concentrated, exhilarating month of the natural year, especially along the Lake Superior shore.
Week by week in May
April 30 – May 6
- The warbler migration begins to surge — hang oriole and hummingbird feeders now as rose-breasted grosbeaks and Baltimore orioles arrive.
- Large-flowered trillium carpets hardwood hillsides in white, alongside wild geranium, Virginia bluebells, and Jack-in-the-pulpit.
- Outdoor markets reopen in force with asparagus at its tender peak, plus rhubarb, spring greens, radishes, and a flood of vegetable seedlings.
May 7–13
- The warbler migration crests — wave after wave of brilliant songbirds pours through Park Point in Duluth and every wooded park and yard statewide.
- Lilacs come into fragrant bloom in the metro, and wild lupine opens on the sandy soils as the wildflower season broadens.
- Keep frost protection ready — the metro's last frost arrives around mid-month, and warm-season transplants must wait until it passes.
May 14–20
- The prairie comes alive with returning bobolinks bubbling over the grass, western meadowlarks whistling from fenceposts, and buzzing dickcissels.
- After the mid-May last frost passes in the metro, set out tomatoes, peppers, and squash, and direct-sow beans and corn into warming soil.
- The first home-grown monarchs' parents arrive from the south, laying eggs on emerging milkweed, while eastern tiger swallowtails patrol the edges.
May 21–27
- Common loons are now on nests, black terns work the marshes, and the spring dawn chorus reaches its absolute fullest in the breeding woods.
- Prairie smoke and the last spring ephemerals fade as the canopy closes; garden iris, peonies, and the first roses come into their own.
- Chokecherry and wild plum bloom white along fencerows, and the red and white pines push up pale 'candles' of new growth.
May 28 – June 3
- In the far north, late frost danger lingers, but breeding is in full swing — hermit thrushes and winter wrens sing in the North Woods evening.
- Across the rest of the state the frost is past — finish setting out warm-season crops and direct-sow successive rounds of beans and cucumbers.
- Oaks, hickories, and black walnut finally leaf out, the last to do so, completing the canopy as oak pollen dusts the air.
Birds This Month
May is the single best birding month in Minnesota, and the headline is the warbler migration. Wave after wave of tiny, brilliant songbirds pour north through the state — yellow, magnolia, chestnut-sided, blackburnian, black-throated green, Cape May, and dozens more — peaking in the second and third weeks. The legendary funnel is Park Point in Duluth and the North Shore, where migrants concentrate along Lake Superior, but every wooded park and yard fills with birds. Along with warblers come rose-breasted grosbeaks, Baltimore and orchard orioles, scarlet tanagers, indigo buntings, ruby-throated hummingbirds, and a flood of flycatchers, vireos, and thrushes.
On the water, common loons are now nesting, black terns and Forster's terns work the marshes, and shorebirds pass through on mudflats and flooded fields. The prairie comes alive with returning bobolinks, meadowlarks, and dickcissels. Hang an oriole feeder and a hummingbird feeder by the first week of May, and listen at dawn — the spring chorus is at its absolute fullest.
What's Blooming
May is the climax of the spring-ephemeral display and the start of the broader wildflower season. In the hardwood forests of the southeast, central Big Woods, and the maple-basswood north, large-flowered trillium carpets whole hillsides in white, alongside wild geranium, Virginia bluebells, Jack-in-the-pulpit, wild columbine, false rue anemone, and trout lily. Marsh marigold glows gold in wet woods and ditches statewide.
As the canopy closes, the show shifts to the edges and openings: wild lupine blooms on sandy soils, prairie smoke and pasque flower open on dry prairie remnants in the west, and lily-of-the-valley and lilacs scent the gardens. Lilac bloom — a beloved May marker — usually peaks mid-to-late month in the metro. Garden tulips, daffodils, and the first bearded iris are at their height. The forest-floor ephemerals fade fast once the trees leaf out, so the first half of May is the time to see them.
Garden This Month
May is the big planting month, but it pivots on the last-frost date — and in Minnesota that's not until mid-to-late May for most of the state, later in the north. Early in the month, keep planting and harvesting cool-season crops: peas, lettuce, spinach, radishes, carrots, beets, potatoes, and onions all thrive. Harden off your warm-season seedlings over a week of increasing outdoor exposure so they don't shock when transplanted.
Once the frost date passes (around mid-May in the metro, later northward), set out tomatoes, peppers, eggplant, squash, cucumbers, and basil, and direct-sow beans, corn, and melons into warm soil. Watch the forecast vigilantly — a late frost can still strike, so keep row cover or old sheets ready. In the flower garden, plant annuals after frost, divide and move perennials, and mulch beds to hold the moisture that the coming summer heat will demand.
Zone 3b (far north & Iron Range): the last frost can come as late as early June here, so keep warm-season crops protected. Direct-sow hardy greens, peas, and root crops now, and wait until very late May or early June to set out tomatoes, peppers, and squash under cover.
Zone 4b (most of the state): the last frost is typically mid-to-late May. Keep cool-season crops growing and harden off warm-season transplants, setting out tomatoes, peppers, and squash only after the frost date passes near the end of the month — watch the forecast and cover for late cold snaps.
Zone 5a (Twin Cities metro & southeast): the warmest zone reaches its last frost mid-month. After about May 15–20, set out tomatoes, peppers, eggplant, and cucurbits, direct-sow beans and corn, and plant warm-season flowers — keeping an eye out for any late frost into the third week.
What's at the Farmers Market
May is when Minnesota's outdoor farmers markets reopen in force — the Mill City Farmers Market and the big St. Paul market downtown come fully back to life, and the smaller markets from Rochester to Duluth follow. The first true field harvest is still slim this far north, so the headliner is rhubarb, thriving in the cold and stacking up in red bundles, joined by the season's first cold-frame and high-tunnel spinach, salad mix, arugula, radishes, green onions, and overwintered scallions. Asparagus arrives late in the month and runs short and precious in Minnesota's brief window, and the earliest high-tunnel tomatoes and cucumbers from greenhouse growers around the metro start to appear.
The real engine of a Minnesota May market, though, is the bedding-plant and seedling rush: vendors and the state's wholesale greenhouse growers flood the tables with vegetable starts, herbs, hanging baskets, and especially the native prairie perennials — milkweed, coneflower, blazing star, and prairie grasses — that gardeners here plant heavily after the mid-to-late-May frost date. Look, too, for the last jars of spring maple syrup from the sugarbushes that ran in March and April, and for honey, eggs, and the first cut tulips and lilacs. These season-opening weekends are the most crowded, festive mornings of the early market year.
Night Sky This Month
May's mild nights and the late sunset of approaching summer make for relaxed stargazing, though the nights are shortening fast toward the solstice. The spring sky is at its best: the Big Dipper rides high overhead, the bright orange star Arcturus in Boötes commands the eastern sky, and blue-white Spica in Virgo and the keystone of Hercules climb behind it. Late in the night, the first of the Summer Triangle stars, Vega, clears the eastern horizon.
The Eta Aquariid meteor shower — debris from Halley's Comet — peaks in early May, though its low radiant makes it a modest show from Minnesota's latitude, best in the pre-dawn hours. Late-spring nights remain good for the northern lights when geomagnetic activity spikes, especially from the dark north country. As always, the printable Minnesota night-sky guide lists this year's exact meteor-peak dates, planet positions, and aurora outlook for your part of the state.
Butterflies & Pollinators
Minnesota's signature May butterfly story unfolds on the dry prairie remnants and oak savannas, where fire-shaped, sandy ground brings out scarce specialists weeks before the summer crowd. On the gravel hill prairies of the Minnesota River valley and the quartzite barrens of Blue Mounds State Park, the first brood of the olympia marble drifts low over rock-cress, the cobweb and Leonard's-relative skippers dart through warming bunchgrass, and the elfins — the eastern pine elfin and brown elfin — perch on jack-pine and blueberry edges in the central sand country. The federally threatened Dakota skipper is still a larva in these same native-prairie sods, weeks from its late-June flight, a reminder of why Minnesota's unplowed prairie matters.
Statewide, the woodland-edge brushfoots build through the month: fresh eastern tiger swallowtails and Canadian tiger swallowtails (the smaller northern species, common in the Arrowhead) patrol forest edges, with spring azures, silvery blues, and pearl crescents over open ground. The first monarchs trickle up from the south to lay on emerging milkweed — arriving in the Twin Cities weeks ahead of the North Woods — while worn, overwintered mourning cloaks and Compton tortoiseshells still nectar at willow catkins and sap flows on warm afternoons.
What to plant for them is in the Minnesota native plants guide
Trees This Month
May is full leaf-out across Minnesota, the woods transforming from bare gray to full green within a few weeks (later in the north). The flowering trees take center stage: serviceberry (Juneberry), wild plum, and chokecherry bloom white along woodland edges and fencerows, crabapples and orchard apples burst into pink and white in the south, and the fragrant flower clusters of black cherry and hawthorn follow.
The conifers push their new growth — red and white pines send up pale 'candles' of new shoots, and the tamaracks are fully green again in the bogs. Oaks, hickories, black walnut, and green ash are the last to leaf out, finally unfurling as the frost danger ends, and oak pollen dusts the air. By late May the canopy has closed over the forest floor, ending the brief sunlit window that the spring ephemerals depended on.
The Minnesota native plants guide covers what grows with them
Weather & Daylight
Across Minnesota, a typical May day averages a high near 67°F and a low near 43°F, with about 3.5 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Mild and blooming, soft breezes and frequent showers with evenings comfortable enough to sit outside.
| Average high | 67°F |
|---|---|
| Average low | 43°F |
| Precipitation | 3.5 in |
| Sunrise (mid-month) | 5:46 CT |
| Sunset (mid-month) | 20:39 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 Minnesota's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Minnesota guides
The complete Minnesota birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: May in Mississippi · May in Missouri · May in Montana