A slightly rocky stretch of Day Boulevard shoreline between Carson Beach and Castle Island, more suited to walking and sunbathing on the grassy strip along the sea wall than to swimming given the rockier bottom. A $2 million renovation added new plantings and an improved sea wall.
What to expect
Swimming
Allowed water tested by the state
Season
Year-round, dawn to dusk
Managed by
Massachusetts Department of Conservation and Recreation (DCR), South Region
WebsiteGetting in
Access points along this beach
Murphy Rink access
Day Boulevard side
Sailing Center access
Castle Island side, near the Harry McDonough Sailing Center
What's here
Facilities
Restrooms
Murphy Rink (Day Boulevard side); Near Sullivan's / Harry McDonough Sailing Center (Castle Island side)
Not here
No picnic area
No picnic facilities noted directly on this segment; grassy area along the sea wall only
Tides & weather
Tide and sun: NOAA astronomy · forecast: NWS, up to 7 days
Common questions
Is M Street Beach in Boston open today?
Open, no advisory on record in the latest MA DPH posting (updated 2026-09-13). MA DPH is the authority. Check the status the morning you go.
Are there restrooms at M Street Beach?
Public restrooms are listed near the beach. Seasonal hours are common, so they may be closed off-season.
What rules should I know at M Street Beach?
Shoreline is slightly rocky, footwear recommended for swimming.
Can you swim at M Street Beach?
Yes. M Street Beach has no swimming advisory in the latest MA DPH posting (updated 2026-09-13). Check again the morning you go.
Is there an entry fee at M Street Beach?
No, entry is free.