Massachusetts boating conditions
Cape Cod Bay marine forecast
One place to compare marine conditions from Plymouth and Sandwich around to Wellfleet and Provincetown.
For the rest of today: Cape Cod Bay S 10–15 kt, gusts 20, seas 2–3 ft. Best day this week: Fri, Nov 6. Fri, Nov 6 is the mildest day. At least one period is still Caution.
Forecast checked Thu, Nov 5, 2026, 3:04 AM EST · National Weather Service coastal waters forecast issued 1:03 AM EST · harbor briefings updated 3:04 AM EST · water temperature unavailable
Right now
Cape Cod Bay conditions today
Each flag is that harbor's live call. Zone labels use the coastal waters forecast for the rest of today.
- Cape Cod Bay, MA (221)
NWS coastal waters forecast
Cape Cod Bay forecast by zone
Each period is scored with the same limits as the harbor pages: 15 kt wind, 20 kt gusts, 2.5 ft seas. Thunderstorms or reduced visibility turn a period to Caution.
From the canal entrance around to Provincetown
No advisoryOfficial NWS text for each zone
Cape Cod Bay (ANZ231)
Rest Of Tonight: SW winds around 10 kt. Seas around 2 ft. Wave Detail: SW 1 foot at 3 seconds and SE 1 foot at 10 seconds.
Thu: S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and SE 1 foot at 10 seconds. Patchy fog in the morning with vsby 1 NM or less.
Thu Night: S winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft. Wave Detail: SW 2 ft at 3 seconds and SE 1 foot at 9 seconds. Rain likely after midnight.
Fri: S winds around 10 kt with gusts up to 20 kt. Seas around 2 ft. Wave Detail: SW 1 foot at 3 seconds and SE 1 foot at 8 seconds. Patchy fog. Rain. Vsby 1 to 3 NM.
Fri Night: S winds 5 to 10 kt. Seas around 2 ft in the evening, then 1 foot or less. Wave Detail: S 1 foot at 2 seconds and SE 1 foot at 8 seconds, becoming S 1 foot at 2 seconds and SE 1 foot at 9 seconds. Patchy fog. Rain. Vsby 1 to 3 NM.
Sat: S winds 5 to 10 kt, becoming NW in the afternoon. Seas 1 foot or less, then around 2 ft in the afternoon. Wave Detail: SW 1 foot at 2 seconds and SE 1 foot at 8 seconds, becoming NW 1 foot at 2 seconds and E 1 foot at 9 seconds. Rain, mainly in the morning. Patchy fog in the morning.
Sat Night: NW winds 10 to 15 kt, increasing to 15 to 20 kt after midnight. Gusts up to 25 kt. Seas 2 to 3 ft. A chance of rain after midnight.
Sun: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. A chance of rain.
Sun Night through Mon Night: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height.
Five-day trend
Wind and seas across Cape Cod Bay
Day and night bars for each zone, in the same wind and seas chart style as a harbor page. A missing bar is a period the forecast did not quantify.
Cape Cod Bay
Dashed limit on the harbor pages: 15 kt. Bars are the top of the forecast range.
Dashed limit on the harbor pages: 2.5 ft. Bars are the top of the forecast range.
Harbor-level briefings
Compare conditions around Cape Cod Bay
Cape Cod Bay harbors
From the western bay and canal entrance to the Outer Cape.
A broad but shoal harbor system shared with Kingston and Duxbury, entered through a long marked channel.
8 ktseas 2 ft56°F water
Conditions are Caution now and remain evaluated through 7:04 AM.
A protected basin at the east end of the Cape Cod Canal, shaped by canal currents, commercial traffic, and Cape Cod Bay conditions.
8 ktseas 2 ft56°F water
Conditions are Caution now and remain evaluated through 7:04 AM.
A small north-side Cape Cod harbor opening into Cape Cod Bay through a narrow, tide-sensitive marked channel.
8 ktseas 2 ft56°F water
Conditions are Caution now and remain evaluated through 7:04 AM.
A spacious Outer Cape harbor behind Great Island, entered across shoal water from Cape Cod Bay through a long marked approach.
8 ktseas 2 ft56°F water
Conditions are Caution now and remain evaluated through 7:04 AM.
A spacious natural harbor at the tip of Cape Cod offering one of the region's best-known cruising stops.
9 ktseas 2 ft56°F water
Conditions are Caution now and remain evaluated through 7:04 AM.
Tide charts
Tide charts around Cape Cod Bay
- Low tide 1:30 AM · 0.58 ft · High tide 7:53 AM · 9.86 ft · Low tide 2:01 PM · 0.66 ft · High tide 8:19 PM · 9.64 ft—water unavailable
- Low tide 1:25 AM · 0.3 ft · High tide 7:48 AM · 9.02 ft · Low tide 1:56 PM · 0.35 ft · High tide 8:14 PM · 8.75 ft—water unavailable
- Low tide 1:29 AM · 0.12 ft · High tide 7:50 AM · 10.36 ft · Low tide 2:00 PM · 0.19 ft · High tide 8:17 PM · 10.06 ft—water unavailable
- Low tide 1:31 AM · 0.36 ft · High tide 7:51 AM · 9.65 ft · Low tide 2:00 PM · 0.41 ft · High tide 8:17 PM · 9.51 ft—water unavailable
The regional picture
One body of water. More than one kind of boat day.
Cape Cod Bay spans a long arc of shoreline, so the same forecast can feel different at Plymouth, the canal entrance, the mid-Cape harbors, and the outer tip. Fetch, wind direction, and the shape of the coast all matter when you are choosing where - and whether - to go.
These harbor briefings put the regional picture beside local wind, waves, tides, observations, and advisories. Start with the bay, then open the destination that best matches your launch point or route.
Before leaving the dock
Three useful checks for Cape Cod Bay
- Look at both wind speed and direction; the exposed side of the bay changes with the breeze.
- Treat the Cape Cod Canal approaches as their own timing problem and check official current information.
- Compare observations around the bay instead of assuming one station describes the whole shoreline.
What this regional guide can - and cannot - do
These pages make it easier to compare the latest available forecast and observation inputs around Cape Cod Bay. They are planning aids, not navigation or safety guarantees. Check the official coastal waters forecast, current observations and notices, local conditions, and your own boat and crew before departure.
See how Boat or Nope builds each call