Massachusetts Nature Guide: May 2026
Data updated: August 2026Sources & method · Corrections
May is the peak of the Massachusetts nature year — the warbler migration crests at Mount Auburn Cemetery and Plum Island, the woods fill with trillium and lady's slippers, the terns return to the Cape, and the last frost finally releases the gardens.
Week by week in May
April 30 – May 6
- Warbler migration crests at Mount Auburn Cemetery — magnolia, blackburnian, black-throated blue, and a dozen more species at eye level.
- The showy pink lady's slipper, the native orchid of acidic woods, begins to open, and the woods hold wild columbine and jack-in-the-pulpit.
- The first monarchs arrive from the south, and eastern tiger swallowtails take to the air over forest edges and gardens.
May 7–13
- Scarlet tanagers, rose-breasted grosbeaks, Baltimore orioles, and indigo buntings pour in, and the dawn chorus reaches its richest of the year.
- Beach plum whitens the dunes of the Cape and North Shore, and lilacs, bearded iris, and the first peonies peak in the gardens.
- After the frost date in the warm zones, harden off and set out tomatoes, peppers, and squash, keeping row cover ready for a late cold snap.
May 14–20
- Common, Least, and the rare Roseate Terns establish colonies on the Cape and Buzzards Bay beaches, and bobolinks sing over the grasslands.
- Flowering dogwood opens its white bracts, fragrant black locust drapes the roadsides, and crabapples and apples burst into pink and white bloom.
- Local asparagus is at its tender, sweet peak at the farmers markets, alongside rhubarb and the first spring greens.
May 21–27
- Across central Massachusetts the frost date passes — set out the warm-season transplants and direct-sow beans, corn, and melons into warming soil.
- Great spangled fritillaries and pearl crescents emerge in the meadows, and specialty elfins and hairstreaks fly in the pine barrens.
- Wild lupine blooms on sandy ground and blue flag iris opens in the marshes as the woodland ephemerals fade under the closing canopy.
May 28 – June 3
- Ruby-throated hummingbirds work the feeders, wood thrushes and veeries sing in the forest, and warbler migration tapers as breeding settles in.
- Eastern white pine pushes pale candles of new growth, and the oaks, last to leaf out, finally unfurl and dust the air with pollen.
- Even the Berkshires reach their frost-free date now — set out the last warm-season crops and mulch beds against summer drought.
Birds This Month
May is the single best birding month in Massachusetts, headlined by the warbler migration. Mount Auburn Cemetery in Cambridge becomes the most famous migrant trap in New England, drawing crowds of birders to see dozens of warbler species at eye level — magnolia, blackburnian, Cape May, bay-breasted, chestnut-sided, black-throated blue and green, Canada, prothonotary, and many more. With them come scarlet tanagers, rose-breasted grosbeaks, Baltimore and orchard orioles, indigo buntings, and a flood of vireos, thrushes, and flycatchers. Plum Island and the Quabbin host equally rich movements.
On the coast, the breeding season explodes: Common, Least, and the rare Roseate Terns establish colonies on the beaches and islands of the Cape and the Buzzards Bay region, Piping Plovers nest in the dunes, and Willets and American Oystercatchers patrol the marshes. Inland, ruby-throated hummingbirds hit feeders, wood thrushes, ovenbirds, and veeries sing in the forest, and bobolinks return to the grasslands. Bird at dawn — the spring chorus is at its absolute fullest.
What's Blooming
May carries Massachusetts wildflowers from the forest floor out into the open country. Early in the month the rich woods still hold red and painted trillium, wild geranium, wild columbine on the ledges, jack-in-the-pulpit, mayapple, Solomon's seal, foamflower, and the much-loved pink lady's slipper, the showy native orchid of the acidic pine and oak woods. Starflower, Canada mayflower, and wild oats carpet the understory before the canopy closes.
On the coast, the dunes whiten with beach plum and the first beach heather, and roadsides fill with blue-eyed grass, golden Alexanders, wild lupine on sandy ground, buttercups, and drifts of dame's rocket. Gardens reach their late-spring peak with bearded iris, peonies, alliums, lilacs, and the first roses and azaleas. The flowering trees still glow with crabapple, dogwood, and lilac. The first half of May is the last chance for the woodland ephemerals before the leaves shade them out.
Garden This Month
May is the big planting month in Massachusetts, pivoting on the last-frost date — early-to-mid May on the warm Cape, mid-to-late May across the center, and late May up in the Berkshires. Early in the month, keep harvesting and succession-sowing cool-season crops: peas, lettuce, spinach, radishes, carrots, beets, and chard. Harden off warm-season seedlings over a week of increasing outdoor exposure so they don't shock when transplanted.
Once your frost date passes, set out tomatoes, peppers, eggplant, squash, cucumbers, and basil, and direct-sow beans, corn, and melons into warm soil. A late frost can still strike well into May, especially inland, so keep row cover ready. In the flower garden, plant annuals after frost, divide and move perennials, stake peonies, and mulch beds to hold the moisture summer demands. Watch for slugs in the wet New England spring and stay ahead of weeds as everything surges into growth.
Zone 5b (Berkshires & western hills): the last frost can linger to late May here, so keep warm-season crops protected — set out tomatoes, peppers, and squash only after about May 25–30, and keep row cover ready for a late mountain cold snap.
Zone 6a (central Massachusetts): the last frost typically passes by mid-to-late May — harden off and set out tomatoes, peppers, and cucurbits after about May 20, direct-sow beans and corn, and keep cover handy for a late dip.
Zone 7a (Cape Cod & the Islands): the warmest, earliest zone reaches its safe frost date in early-to-mid May — set out all warm-season transplants and direct-sow beans, corn, and melons into warming, sandy soil.
What's at the Farmers Market
May belongs to the Connecticut River Valley, the sandy alluvial bottomland around Hadley, Whately, and Hatfield that New Englanders have long called the Asparagus Valley. The famous tender Hadley asparagus hits the Pioneer Valley stands at its few-week peak, and the town's Hadley Asparagus Festival turns the crop into a local rite of spring. The reopening markets reflect the state's geography: Copley Square and Union Square in Somerville draw on Eastern Massachusetts growers, while the valley markets at Northampton and Amherst overflow with field-grown rhubarb, river-bottom spinach, leaf lettuce, arugula, radishes, scallions, and pea shoots, with the warm-soil Cape and South Coast farms offering the season's earliest field strawberries late in the month.
This is also the height of the New England seedling and plant-sale season, when valley greenhouses and coastal nurseries roll out flats of tomato, pepper, and herb starts, hardy native perennials, and hanging baskets for gardeners timing the frost date. Look for raw-milk cheese, maple syrup from the late-winter sugaring, local honey, eggs, and pasture-raised meats rounding out the stalls. Snap a Hadley spear in the field and it bends, then breaks clean — the sign of a stalk cut that same morning. The Pioneer Valley markets are at their fresh, energetic, unmistakably Massachusetts best.
The Massachusetts native plants guide covers what grows here
Night Sky This Month
May's mild nights make for relaxed Massachusetts stargazing, though the nights keep shortening toward the solstice. The spring sky is at its best: the Big Dipper rides high overhead, and its handle arcs to brilliant orange Arcturus in Boötes, then on to blue-white Spica in Virgo. The keystone of Hercules climbs in the east, carrying the great globular cluster M13 — a fine binocular and telescope target — and late in the night the first Summer Triangle star, Vega, clears the 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 Massachusetts latitudes, best in the pre-dawn hours. The deepening warmth and the rising arc of the Milky Way later in the night make for pleasant evenings out at a dark site like the Berkshires, the Quabbin, or the outer Cape. For this year's exact meteor-peak dates and planet positions over Massachusetts, see the printable Massachusetts night-sky guide.
Butterflies & Pollinators
May is when the Massachusetts butterfly season truly opens. The big arrival is the monarch — the first generation moves up from the south in late May, the females laying eggs on emerging milkweed to launch the summer's home-grown broods. They join a building cast: the year's eastern tiger swallowtails patrol forest edges and gardens, black swallowtails appear over fields and herb beds, red admirals and painted ladies arrive as migrants, and small spring azures, cabbage whites, and orange sulphurs are common in open ground.
In the pine barrens of Cape Cod and the southeast, specialty species fly: elfins, the Hessel's hairstreak in Atlantic white cedar swamps, and the rare frosted elfin in lupine fields. The first great spangled fritillaries and pearl crescents appear in meadows, and the blue-black red-spotted purple glides along sunlit woodland trails. Watch dame's rocket, lilac, and wild phlox for nectaring butterflies on warm afternoons, and establish native milkweed now — the monarchs laying eggs this month begin the generations that make the great fall migration.
What to plant for them is in the Massachusetts native plants guide
Trees This Month
May is full leaf-out across Massachusetts, the woods turning from bare gray to deep green within a few weeks — later up in the Berkshire hill towns. The flowering trees take center stage: flowering dogwood opens its white bracts in the understory, fragrant black locust drapes the roadsides in white, crabapples and orchard apples burst into pink and white bloom, and horse chestnut, black cherry, and hawthorn follow. Native highbush blueberry blooms in the wetlands and barrens.
High in the canopy, the oaks and hickories — last to leaf out — finally unfurl and dust the air with yellow pollen, and the eastern white pine, the state's signature tree, pushes its pale new candles of growth. American elm and the maples fill out their full canopies. By late May the leaf canopy has closed over the forest floor, ending the brief sunlit window the spring ephemerals depended on and setting the green stage for the long Massachusetts summer.
The Massachusetts native plants guide covers what grows with them
Weather & Daylight
Across Massachusetts, a typical May day averages a high near 68°F and a low near 46°F, with about 3.7 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Pleasantly warm afternoons near 68F meet cool, comfortable evenings in the mid-40s, with steady rain keeping everything green.
| Average high | 68°F |
|---|---|
| Average low | 46°F |
| Precipitation | 3.7 in |
| Sunrise (mid-month) | 5:25 ET |
| Sunset (mid-month) | 19:59 ET |
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 (ET).
Next month's version of this page, by email
One short note when Massachusetts's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Massachusetts guides
The complete Massachusetts birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: May in Michigan · May in Minnesota · May in Mississippi