Month-by-month Martha's Vineyard weather: air temps, ocean temps, rain, snow, sunshine, humidity and wind. Plan your visit with real climate data.
Martha's Vineyard sits 7 miles off the southern coast of Cape Cod in the Atlantic Ocean, and that water makes all the difference. The island's maritime climate keeps summers cooler and winters milder than mainland Massachusetts: typically 8–12°F warmer in winter and 5–8°F cooler in summer than Boston or Providence. Annual rainfall averages 47.7 inches, spread fairly evenly across all 12 months, and snowfall runs about 25 inches per year: significant, but nothing like inland New England.
The result is a real four-season island. Summer is warm and breezy. Fall is crisp and clear. Winter is wild and raw. Spring comes late. Below are the actual numbers, month by month.
Already know when you're going? Jump to the best time to visit guide for crowd and price context alongside the weather.
The table below covers the first half of the year. Columns show average high and low temperatures (°F), ocean surface temperature (°F), typical rain days per month, snow days, daily sunshine hours, average afternoon humidity (%), average wind speed (mph), recommended clothing, and a one-line summary.
Month
Avg High °F
Avg Low °F
Ocean °F
Rain Days
Snow Days
Sun Hrs/Day
Humidity %
Wind mph
What to Wear
Summary
January
40
26
41
11
5
5
73%
17
Heavy coat, hat, gloves, waterproof boots
Cold, raw, and quiet: the island at its most remote.
February
42
27
38
9
4
6
71%
17
Heavy coat, hat, gloves, waterproof boots
Coldest ocean of the year; nor'easters possible; fewer rain days than January.
March
46
32
39
11
4
7
71%
16
Warm layers, windproof jacket, waterproof boots
Windy and transitional: the island's most unpredictable month.
April
55
40
45
11
0
8
70%
15
Light jacket, fleece, layers
Snow is gone; daffodils bloom; island reopens gradually for the season.
May
65
49
53
12
0
8
74%
13
Layers, light jacket, comfortable walking shoes
Mild and green: most rain days of spring, but very pleasant between showers.
June
74
58
61
10
0
9
79%
12
Shorts, t-shirts, light sweater for evenings, light rain layer
Long days, warm and beautiful, but the foggiest month of the year.
Monthly Climate Data: July–December
The second half of the year brings summer's peak warmth, the clearest skies of the year in September and October, and then the slow return of winter. Ocean temperatures peak in August and hold warmth well into September.
Month
Avg High °F
Avg Low °F
Ocean °F
Rain Days
Snow Days
Sun Hrs/Day
Humidity %
Wind mph
What to Wear
Summary
July
80
64
68
7
0
9
79%
12
Swimsuit, shorts, t-shirt, light sweater for evenings
Peak summer: fewest rain days of the year, ocean warm enough to swim.
August
80
64
70
8
0
8
79%
12
Swimsuit, shorts, t-shirt, light sweater for evenings
Warmest ocean of the year and calmest winds; the busiest month on the island.
September
74
58
67
9
0
8
79%
13
Layers, light jacket for evenings, swimsuit still useful
Clearest skies, warm ocean, fewer crowds: the month islanders keep for themselves.
October
64
48
62
11
0
7
76%
15
Fleece, light jacket, comfortable layers
Fall foliage, excellent sunshine ratio, and a still-swimmable ocean early in the month.
November
54
40
55
11
0
5
73%
17
Warm jacket, hat, layers
Off-season arrives; winds pick up and most summer businesses close.
December
46
31
47
12
5
5
74%
17
Heavy coat, hat, gloves, waterproof boots
Wettest month of the year; first snows possible; Christmas in Edgartown is the month's big weekend.
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Ocean Temperature on Martha's Vineyard
Summer · the water warms slowlyPhoto by MV Vacation
The Sound side warms first and stays swimmable into September. The Atlantic beaches on the south shore run colder and rougher right through the season.
Martha's Vineyard's ocean temperatures tell a different story than you might expect. The island sits at the boundary between colder Gulf of Maine waters and the warmer offshore flow influenced by the Gulf Stream. That interaction creates a thermal buffer: the water never gets as cold as Maine, but it also never reaches the bath-like warmth of the Carolina coast.
The swimming season runs July through September only. Ocean temps reach 68°F in July and peak at 70°F in August, warm enough for comfortable swimming, though still noticeably cooler than a heated pool. September holds at 67°F, which most swimmers find perfectly acceptable. By October, the water drops to 62°F: brave souls only. November's 55°F is wetsuit territory.
One counterintuitive pattern: September ocean water is warmer than May ocean water by 14°F (67°F vs 53°F). This is thermal lag: the ocean takes months to absorb summer heat and releases it slowly into fall. If swimming is a priority, September is a far better month than June despite having similar air temperatures.
June is the foggiest month on the island for exactly this reason. Warm, humid air moving off the warmer land masses meets the still-cool ocean water, and the temperature differential creates persistent sea fog, sometimes burning off by midday, sometimes hanging all day. It is pretty, but plan around it.
Real snow is rare here and seldom lasts. What the island does get is wind and the odd coastal storm, which can shut the ferries down for a day at a time.
Martha's Vineyard averages 25.3 inches of snow per year, enough to be significant, but the maritime climate means most winter precipitation falls as rain or mixed precipitation rather than clean snow. True accumulating snowstorms are memorable events rather than weekly occurrences.
Island-wide · on the busPhoto by MV Vacation
The state emergency agency rides the VTA: a MEMA poster on a Route 13 bus in September 2026, mid hurricane season, with the three things it asks of everyone on the coast.
Nor'easters hit the island one to three times per winter, typically between November and March. These storms arrive from the northeast with howling winds, heavy precipitation, and rough surf. They can dump 12–18 inches of snow or deliver damaging rain and coastal flooding depending on the storm track. The most severe nor'easters cause ferry cancellations and road closures. The February 2026 blizzard dropped over 18 inches on the island, one of the heaviest single-storm totals in recent years.
The island's hurricane exposure is real. Hurricane Bob in 1991 remains the benchmark storm: 100+ mph gusts, significant structural damage, and a permanent place in island memory. The off-season guide covers storm preparedness for winter visitors.
Looking at rainfall across the year, July is the driest month with only 7 days of measurable rain, one reason it's so popular for vacations. December is the wettest, with 12 rain days on average. The difference between the driest and wettest months is relatively small compared to continental climates, which reflects the maritime pattern of year-round moisture.
Total annual rainfall of 47.7 inches is distributed fairly evenly, so no month is truly dry. Bring a light rain layer any time of year.
Wind and Sunshine
The island runs breezyPhoto by MV Vacation
The rocky shore below the cliffs at Aquinnah. The Vineyard is a windy place, and a layer earns its place even in July.
Wind is a constant presence on Martha's Vineyard. The island's exposed position in the Atlantic means the wind rarely stops entirely; it's part of what makes summer afternoons so refreshing and winter days so biting.
March is traditionally the windiest month on the island, with persistent westerly and northwesterly winds and frequent gusts. January and February record the highest wind speeds in actual measurements (both averaging 17 mph), but March's wind feels relentless because it combines with the transition from winter to spring. August is the calmest month, when the Bermuda High pressure system settles over the Atlantic and delivers stable, gentle southwest breezes: ideal sailing and beach conditions.
Sunshine follows a simple pattern. June and July both average 9 hours of sunshine per day, the island's peak. Long June days (nearly 15 hours of daylight around the solstice) mean even foggy mornings often yield beautiful afternoons. September and October deliver the clearest skies, with the highest sunshine ratio (percentage of possible daylight hours that are actually sunny) of any months, around 60–61%. That is why fall visitors tend to come back.
Daylight extremes are significant at this latitude:
Summer solstice (late June): 15 hours and 10 minutes of daylight; evening light until nearly 9pm
Winter solstice (late December): 9 hours and 5 minutes of daylight; dark by 4:15pm
For June visits, the long evenings are the reward. For July and August, plan beach time in the afternoon when sea breezes peak. September and October bring the clear fall light photographers wait for.
Season-by-Season Overview
Fall · the island’s best lightPhoto by MV Vacation
Ask a local and they will point you to September and October: warm afternoons, cool nights, and the summer crowds long gone.
Peak Season: Late June through Labor Day
This is the island at full throttle. Every restaurant is open, every beach is staffed, ferries run at maximum frequency, and prices are at their highest. Air temperatures are reliably warm (highs in the mid-70s to low 80s), the ocean is swimmable, and the light is at its best. The tradeoff is crowds: beaches fill by 10am on weekends, restaurants require advance reservations, and ferry standby lines can stretch for hours. Book everything as early as possible. See the spring guide for advance planning tips that apply to summer bookings too.
Shoulder Season: May–June and September–October
The months islanders would keep to themselves if they could. Weather in May and early June is mild and green, with wildflowers blooming and restaurants running full menus without the summer crush. September and October bring the finest weather of the year, most years: clear skies, warm ocean (September), fall foliage (October), and hotel prices that drop 30–50% from August peaks. Some businesses begin closing in mid-October, so check hours before you go. The September guide and October fall foliage guide have full details on what's open and what to do.
Off-Season: November through April
This is the island as islanders live it. Year-round residents make up nearly the entire population, most summer businesses are shuttered, and the landscape is raw and beautiful. Accommodation prices drop dramatically, and the few restaurants that stay open are excellent. Winter hiking, birding, and storm-watching from the cliffs are worth the trip. The risks are real too: weather can change fast, ferry service may be disrupted, and you need to plan meals around limited hours. The winter off-season guide has the details.
Island tip of the dayInsiderNo. 84 of 86New tip at midnight, island time
A 502-foot breach opened at Norton Point on January 1, 2026, cutting the sand link between Katama and Chappaquiddick: the Chappy Ferry is once again the only way across, likely for years. OSV drivers should check current beach access with the town of Edgartown.
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Disclaimer: The information in this article is provided for general guidance only and was accurate at the time of writing. Beach conditions, hours, prices, lifeguard schedules, ferry fares, and business operations change frequently and without notice. Ocean swimming carries inherent risks including rip currents, undertow, and cold water shock. Always verify current conditions with official local sources before your visit. MV Vacation assumes no responsibility for any loss, injury, or inconvenience resulting from the use of this information. Swim only where lifeguards are on duty, supervise children at all times near water, and follow all posted safety signs.
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