Massachusetts Nature Guide: August 2026
Data updated: August 2026Sources & method · Corrections
August is late summer in Massachusetts — fall shorebird migration peaks on the mudflats, monarchs build toward their southward push, the goldenrod and Joe-Pye weed bloom, and the corn-and-tomato harvest hits its glorious peak.
Week by week in August
July 30 – August 5
- Fall shorebird migration builds on the flats — semipalmated and least sandpipers, plovers, and whimbrel gather at South Beach and Monomoy.
- The first big bloom of goldenrod opens in the fields and on the coast, joined by Joe-Pye weed, ironweed, and the earliest asters.
- Peak abundance: harvest tomatoes, corn, beans, and squash daily, watch for late blight in humid weather, and sow fall spinach and lettuce.
August 6–12
- The Perseid meteor shower peaks around August 12 — the year's best, with up to 50–60 meteors an hour from a dark site after midnight.
- Monarchs build toward migration, fueling on goldenrod and asters, with early concentrations gathering along the coast and the Cape dunes.
- The market hits its peak: tomatoes and sweet corn at their best, plus peppers, melons, the first peaches, and the first winter squash.
August 13–19
- Shorebird migration peaks on the mudflats of Plum Island and Monomoy, with thousands of southbound sandpipers and plovers and a chance of rarities.
- Scattered red maples in the swamps flare the first early crimson, and staghorn sumac begins to redden — the earliest hint of fall.
- Swamp milkweed, turtlehead, and pink rose mallow bloom in the wetlands as the goldenrod and aster show intensifies.
August 20–26
- Thousands of tree swallows swirl over the Plum Island marshes at dusk, and common and Roseate Terns stage on the beaches before departing.
- The summer Milky Way is still glorious overhead, with the Sagittarius star clouds and great globular clusters rewarding binoculars from a dark site.
- Common buckeyes become abundant on the coast, joined by painted ladies, red admirals, and the building monarch numbers.
August 27 – September 2
- Plant the fall garden's last quick crops, divide bearded iris and daylilies, and order spring-flowering bulbs as the season's turn comes into view.
- Songbird migration ramps up as warblers, flycatchers, and vireos move south through the woods, and common nighthawks stream over at dusk.
- The first apples and the last of the summer crops overlap at the stands, with peaches, melons, and tomatoes still plentiful.
Birds This Month
August is the great month of fall shorebird migration in Massachusetts, one of the state's premier birding spectacles. The mudflats and beaches of Plum Island, Monomoy NWR, South Beach in Chatham, and the Cape flats fill with thousands of southbound shorebirds — Semipalmated, Least, and White-rumped Sandpipers, Black-bellied and Semipalmated Plovers, Short-billed Dowitchers, yellowlegs, Whimbrel, and the chance of rarities like Hudsonian Godwit or Buff-breasted Sandpiper.
Songbird migration also begins: warblers, flycatchers, and vireos move south through the woods, and nightjars and swallows stage in big flocks — thousands of Tree Swallows swirl over the Plum Island marshes at dusk. Common and Roseate Terns stage on the beaches before departing, sometimes in spectacular numbers around Cape Cod and the Islands. Offshore whale-watch trips remain excellent for shearwaters, storm-petrels, and feeding whales. The shorebird flats are the place to be — visit a couple of hours before high tide for the best concentrations.
What's Blooming
August shifts Massachusetts wildflowers into their late-summer, gold-and-purple phase. The roadsides, old fields, and meadows fill with the first big bloom of goldenrod — many species, from showy Canada goldenrod to the coastal seaside goldenrod — along with Joe-Pye weed and boneset in damp ground, ironweed, black-eyed Susans, Queen Anne's lace, chicory, and the first asters. Brilliant red cardinal flower lines the streams and wet ditches.
Wetlands bloom with swamp milkweed, turtlehead, pickerelweed, water lilies, and pink rose mallow in the salt marshes. On the coast, the dunes glow with seaside goldenrod and beach rose hips, and in the southeastern bogs the native cranberry sets its ripening fruit. Gardens reach their late-summer crescendo with black-eyed Susans, coneflowers, phlox, sunflowers, sedum, and zinnias. The goldenrod and asters now coming on are the crucial nectar that fuels the migrating monarchs and the late-season bees.
Garden This Month
August is peak abundance and the start of the fall pivot in the Massachusetts garden. Harvest is at its fullest: tomatoes, peppers, eggplant, sweet corn, beans, summer squash, cucumbers, melons, potatoes, onions, and the first winter squash. Pick daily, water deeply in dry spells, and watch closely for late blight on tomatoes and potatoes in humid weather, plus the usual squash bugs, beetles, and hornworms. Preserve the surplus by freezing, canning, or drying.
It's also prime time to plant the fall garden: direct-sow spinach, lettuce, arugula, radishes, turnips, kale, and Asian greens for a fall harvest, and set out any fall brassica transplants early in the month. Keep up successions of fast crops, and start clearing and composting spent plants as beds open. In the flower garden, deadhead to extend bloom, divide bearded iris and daylilies, and order spring-flowering bulbs to plant in fall. The garden is generous now, but the season's turn is already in view.
Zone 5b (Berkshires & western hills): the first frost can come as early as late September here, so the harvest race is on — keep picking, sow only the fastest fall greens and radishes, and start planning frost protection for tomatoes and peppers.
Zone 6a (central Massachusetts): peak harvest with frost still a month or more off — sow fall spinach, lettuce, radishes, and Asian greens, plant garlic-bed cover, and keep watering and harvesting heavily.
Zone 7a (Cape Cod & the Islands): the long, warm coastal season runs well into fall — there is still time for fall brassica transplants, plenty of succession greens, and a final round of bush beans before the late first frost.
What's at the Farmers Market
August is the peak of the Massachusetts farmers market year, the stands groaning with the full summer harvest. Tomatoes and sweet corn are at their absolute best and most abundant, joined by peppers, eggplant, summer squash, cucumbers, green beans, melons, the first winter squash, potatoes, onions, and garlic. The first peaches and plums ripen alongside late blueberries, blackberries, and raspberries.
Fresh herbs, lettuces, greens, and cut flowers overflow the tables, with eggs, honey, cheese, and bread alongside. Buy and eat sweet corn the same day, since the sugars convert to starch fast; keep ears husked and refrigerated until use. Store tomatoes at room temperature, never the fridge. Choose peaches that are fragrant and give slightly at the seam, ripening hard ones on the counter, then refrigerating once soft. This is the month to buy in bulk for freezing and canning — the harvest will never be more plentiful.
The Massachusetts native plants guide covers what grows here
Night Sky This Month
August is the most celebrated stargazing month in Massachusetts, thanks to the Perseid meteor shower, which peaks around August 12 and is the best, most reliable shower of the year — up to 50 to 60 meteors an hour from a dark site, radiating from Perseus in the northeast and best after midnight. The warm summer nights make for comfortable all-night watching from the Berkshires, the Quabbin, or the outer Cape.
The Summer Triangle rides high overhead, and the Milky Way arches in its full glory across the sky, from Cygnus overhead down through the bright star clouds of Sagittarius and Scorpius in the south — a stunning sight from any truly dark location. The galactic core, the Lagoon Nebula, and the great globular clusters reward binoculars and telescopes. As the nights begin to lengthen again, August offers the year's finest combination of dark Milky Way and a major meteor shower. For this year's exact Perseid peak date and planet positions over Massachusetts, see the printable Massachusetts night-sky guide.
Butterflies & Pollinators
August is a peak butterfly month in Massachusetts, with the most important development being the build-up of monarchs. The late-summer generation that will make the great migration to Mexico is emerging now, fueling up on the abundant goldenrod, Joe-Pye weed, and asters, and beginning to drift south — early concentrations gather along the coast and the dunes of Cape Cod and the Islands. Their caterpillars are still feeding on milkweed.
The meadows are alive with great spangled fritillaries, eastern tiger, black, and spicebush swallowtails, abundant skippers, pearl crescents, common wood-nymphs, and clouds of cabbage whites and sulphurs. Migratory painted and American ladies, red admirals, and common buckeyes appear, the buckeyes often common on the coast. Native nectar plants — goldenrod, Joe-Pye weed, ironweed, and coneflower — draw the heaviest traffic now. This is the ideal time to visit a coastal site to watch the first monarchs staging for their remarkable southward journey.
What to plant for them is in the Massachusetts native plants guide
Trees This Month
August finds the Massachusetts forest in its deep, mature late-summer green, but the very first signs of fall begin to appear. In the swamps and wetlands, scattered red maples start turning early — a few branches flaring crimson by month's end, the earliest hint of the coming color. The staghorn sumac raises its deep-red fruit clusters along roadsides, and some sumacs begin to redden their leaves.
The trees are heavy with ripening fruit and nuts now: oak acorns swell and begin to drop, hickory and black walnut nuts fill out, wild black cherry and chokecherry ripen dark fruit, and the native shadbush and dogwood set berries that draw migrating birds. Apple orchards across the state ripen their early varieties. The shorter days and cooling nights are quietly triggering the changes that will, within weeks, ignite the famous Massachusetts fall — but for now the canopy is still mostly green and full.
The Massachusetts native plants guide covers what grows with them
Weather & Daylight
Across Massachusetts, a typical August day averages a high near 80°F and a low near 59°F, with about 4.0 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Still hot and muggy, with highs around 80F and balmy nights near 59F carrying plenty of late-summer rainfall.
| Average high | 80°F |
|---|---|
| Average low | 59°F |
| Precipitation | 4.0 in |
| Sunrise (mid-month) | 5:53 ET |
| Sunset (mid-month) | 19:49 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).
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One short note when Massachusetts's next month turns — what's arriving, blooming, and worth a night outside.
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The complete Massachusetts birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: August in Michigan · August in Minnesota · August in Mississippi