Connecticut · New York boating conditions
Long Island Sound marine forecast
A harbor-by-harbor view of the Long Island Sound marine forecast, from the narrower western Sound through the central reaches to the eastern approaches near the Connecticut River and the Race.
Tonight: Western Sound W 10–15 kt, gusts 20, seas 2–3 ft. Central Sound W 10–15 kt, gusts 20, seas 2–3 ft. Eastern Sound W 10–15 kt, gusts 20, seas 1–2 ft. Best day this week: Wed, Nov 11. Wed, Nov 11 is the mildest day. At least one period is still Caution.
Forecast checked Tue, Nov 10, 2026, 7:33 PM EST · National Weather Service coastal waters forecast issued 6:08 PM EST · harbor briefings updated 7:33 PM EST · water temperature updated 7:24 PM EST
Right now
Long Island Sound conditions today
Each flag is that harbor's live call. Zone labels use the coastal waters forecast for the rest of today.
- Kings PointSSW 8 kt gust 10
- New York Harbor EntranceSW 14 kt gust 16
- BridgeportSW 1 kt gust 3
- New HavenWSW 6 kt gust 8
- New LondonNew London is not reporting right now.
- Block IslandBlock Island is not reporting right now.
NWS coastal waters forecast
Long Island Sound 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.
West of New Haven / Port Jefferson
No advisoryNew Haven / Port Jefferson to the Connecticut River
No advisoryEast of the Connecticut River mouth
No advisoryOfficial NWS text for each zone
Long Island Sound West of New Haven CT/Port Jefferson NY (ANZ335)
Tonight: W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: W 1 ft at 3 seconds.
Wed: W winds 5 to 10 kt. Seas 1 ft or less. Wave Detail: W 1 ft at 2 seconds.
Wed Night: SE winds 5 to 10 kt. Seas 1 ft or less. Chance of rain after midnight.
Thu: E winds 10 to 15 kt with gusts up to 25 kt. Seas around 2 ft. Wave Detail: E 2 ft at 3 seconds. Rain.
Thu Night: NE winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 4 seconds. Rain.
Fri: N winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 3 ft. Wave Detail: N 3 ft at 3 seconds. Rain.
Fri Night: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. Chance of rain.
Sat: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft.
Sat Night: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft, occasionally to 5 ft.
Sun: NW winds 15 to 20 kt. Seas 2 to 3 ft.
Sun Night: N winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft.
Long Island Sound East of New Haven CT/Port Jefferson NY to the Mouth of the Connecticut River (ANZ331)
Tonight: W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: W 2 ft at 4 seconds.
Wed: NW winds 5 to 10 kt, becoming W in the afternoon. Seas around 2 ft in the morning, then 1 ft or less. Wave Detail: W 1 ft at 3 seconds.
Wed Night: SE winds 5 to 10 kt. Seas 1 ft or less. Wave Detail: SE 1 ft at 2 seconds. Slight chance of rain after midnight.
Thu: E winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 3 ft. Wave Detail: E 2 ft at 3 seconds. Chance of rain in the morning, then rain in the afternoon.
Thu Night: NE winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 4 seconds. Rain.
Fri: N winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 4 ft, occasionally to 5 ft. Wave Detail: N 3 ft at 4 seconds. Rain.
Fri Night: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. Chance of rain.
Sat: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. Chance of rain.
Sat Night: NW winds 20 to 25 kt. Seas 2 to 4 ft, occasionally to 5 ft.
Sun: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft.
Sun Night: NW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft.
Long Island Sound East of the Mouth of the Connecticut River (ANZ332)
Tonight: W winds 10 to 15 kt with gusts up to 20 kt. Seas 1 to 2 ft. Wave Detail: W 2 ft at 3 seconds and E 1 ft at 10 seconds.
Wed: W winds 5 to 10 kt. Seas around 2 ft in the morning, then 1 ft or less. Wave Detail: W 2 ft at 3 seconds, becoming W 1 ft at 3 seconds.
Wed Night: S winds around 5 kt, becoming E after midnight. Seas 1 ft or less. Wave Detail: E 1 ft at 2 seconds and W 1 ft at 2 seconds.
Thu: E winds 10 to 15 kt, increasing to 15 to 20 kt in the afternoon. Seas around 2 ft. Wave Detail: E 2 ft at 4 seconds. Chance of rain in the morning, then rain in the afternoon.
Thu Night: NE winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 5 seconds. Rain.
Fri: NE winds around 20 kt with gusts up to 30 kt. Seas 2 to 3 ft. Wave Detail: NE 3 ft at 5 seconds. Rain.
Fri Night: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. Chance of rain.
Sat: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. Chance of rain.
Sat Night: NW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft.
Sun: NW winds 15 to 20 kt with gusts up to 25 kt. Seas around 2 ft.
Sun Night: NW winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft.
Five-day trend
Wind and seas across Long Island Sound
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.
Western Sound
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.
Central Sound
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.
Eastern Sound
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 Long Island Sound
Western Sound
Harbors around the narrower western Sound and its north-shore approaches.
A western Sound harbor with marinas and protected branches close to the New York state line.
8 ktseas 3 ft0°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
A western Long Island Sound harbor with a long marked approach, several yacht clubs, and protected branches near the Mamaroneck waterfront.
14 ktseas 2 ft60°F water
Conditions are Caution now and remain evaluated through 11:33 PM.
A western Long Island Sound port with commercial traffic and nearby shelter in Black Rock Harbor.
1 ktseas 3 ft59°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
Central Sound
Opposite-shore briefings where longer fetch can expose meaningful differences across the Sound.
A broad commercial harbor on central Long Island Sound with protected waters behind its breakwaters.
6 ktseas 3 ft57°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
A compact central Long Island Sound harbor with a protected basin, working marinas, and a marked entrance through shoal coastal water.
6 ktseas 3 ft57°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
A protected north-shore Long Island harbor entered through a narrow, shoal-fringed channel with extensive moorings and quiet water inside.
1 ktseas 3 ft59°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
A broad north-shore Long Island harbor with ferry traffic, a well-defined entrance, protected anchoring areas, and a busy village waterfront.
1 ktseas 3 ft59°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
Eastern Sound and river approaches
Connecticut River destinations and the eastern gateway toward the Race.
A classic lower Connecticut River stop with protected moorings and access to river towns and coves.
5 ktseas 3 ft59°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
A deeply sheltered lower Connecticut River cove reached through the Eightmile River, popular for quiet anchoring and protected cruising.
5 ktseas 3 ft59°F water
Current conditions are outside your 15 kt wind or 2.5 ft seas limit.
A deep harbor at the Thames River mouth with naval, ferry, and commercial traffic.
10 ktseas 2 ft59°F water
Conditions are Caution now and remain evaluated through 11:33 PM.
Tide charts
Tide charts around Long Island Sound
- Low tide 5:21 AM · 0.66 ft · High tide 11:27 AM · 7.44 ft · Low tide 5:56 PM · 0.07 ft · High tide 11:59 PM · 6.53 ft59°Fwater
- Low tide 5:57 AM · 0.68 ft · High tide 11:41 AM · 8.15 ft · Low tide 6:34 PM · -0.06 ft57.6°Fwater
- Low tide 3:34 AM · 0.52 ft · High tide 9:32 AM · 3.19 ft · Low tide 4:21 PM · 0.14 ft · High tide 10:02 PM · 2.35 ft58.8°Fwater
The regional picture
One body of water. More than one kind of boat day.
The official Long Island Sound marine forecast is the National Weather Service coastal waters forecast from the New York (Upton) office, which splits the Sound at New Haven and Port Jefferson into a western zone (ANZ335), a central zone east to the Connecticut River (ANZ331), and an eastern zone beyond the river (ANZ332). The NWS issues it about four times a day and updates it when conditions change; the harbor briefings below refresh with the latest available forecast and observation data through the day.
Long Island Sound changes character from its narrower western end to the broader central water and the stronger tidal exchange near the Race. A wind that leaves one shoreline tucked in can build a longer fetch toward the opposite shore.
Use these briefings to compare both sides of the Sound and the harbor closest to each end of a trip. Sheltered river and harbor readings add useful local context - they do not stand in for conditions on the open crossing.
Before leaving the dock
Three useful checks for Long Island Sound
- Compare the Connecticut and New York shore briefings when a route crosses the Sound.
- Check wind direction with tide and current timing near the Connecticut River mouth and the eastern approaches.
- Use the official coastal waters forecast and current observations for the open-water part of the route.
What this regional guide can - and cannot - do
These pages make it easier to compare the latest available forecast and observation inputs around Long Island Sound. 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.
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