Cos Cob Harbor, CT Weather Forecast and Current Conditions

Day Sky High / Low Precip Wind Humidity
Tue
Jun 30 		Partly Cloudy -º / 73º 11% SW 9 mph 65%
Wed
Jul 1 		Partly Cloudy
View Hourly 		93º / 78º 24% SW 11 mph 61%
12am Partly Cloudy 78º 5% SW 8 mph 60%
1am Mostly Clear 77º 10% SW 8 mph 60%
2am Partly Cloudy 77º 11% SW 8 mph 61%
3am Partly Cloudy 76º 10% SW 9 mph 66%
4am Partly Cloudy 75º 4% SW 8 mph 69%
5am Partly Cloudy 75º 2% SW 9 mph 71%
6am Partly Cloudy 74º 2% SW 8 mph 72%
7am Partly Cloudy 76º 3% SW 9 mph 69%
8am Mostly Cloudy 78º 15% SW 9 mph 66%
9am Partly Cloudy 80º 1% SW 10 mph 64%
10am Mostly Sunny 82º 1% SW 10 mph 62%
11am Mostly Sunny 85º 1% SW 9 mph 60%
12pm Partly Cloudy 87º 0% SW 9 mph 60%
1pm Partly Cloudy 89º 15% SSW 9 mph 59%
2pm Partly Cloudy 90º 15% SSW 9 mph 58%
3pm Partly Cloudy 91º 15% SSW 10 mph 57%
4pm Partly Cloudy 91º 16% SSW 9 mph 57%
5pm Mostly Cloudy 89º 24% S 11 mph 61%
6pm Partly Cloudy 87º 19% S 9 mph 64%
7pm Partly Cloudy 86º 15% S 9 mph 67%
8pm Mostly Cloudy 84º 15% SSW 7 mph 70%
9pm Partly Cloudy 83º 15% SSW 5 mph 70%
10pm Mostly Clear 82º 12% SSW 5 mph 74%
11pm Mostly Clear 81º 10% SSW 5 mph 76%
Thu
Jul 2 		Sunny
View Hourly 		100º / 81º 4% W 9 mph 55%
12am Mostly Clear 81º 7% SW 5 mph 77%
1am Mostly Clear 81º 4% SW 6 mph 79%
2am Mostly Clear 81º 4% WSW 5 mph 78%
3am Clear 80º 4% WSW 5 mph 81%
4am Clear 79º 4% WSW 4 mph 83%
5am Clear 79º 4% WSW 5 mph 84%
6am Sunny 79º 4% WSW 4 mph 83%
7am Sunny 81º 3% W 5 mph 79%
8am Sunny 84º 2% WNW 5 mph 74%
9am Sunny 87º 1% W 6 mph 68%
10am Sunny 89º 1% WNW 6 mph 63%
11am Sunny 92º 1% W 6 mph 59%
12pm Sunny 94º 0% W 7 mph 54%
1pm Sunny 96º 0% WSW 8 mph 48%
2pm Sunny 97º 0% WSW 8 mph 45%
3pm Sunny 98º 5% WSW 8 mph 44%
4pm Sunny 98º 0% WSW 9 mph 44%
5pm Sunny 97º 0% SW 9 mph 43%
6pm Sunny 96º 0% WSW 8 mph 44%
7pm Sunny 94º 0% SW 8 mph 48%
8pm Sunny 91º 1% SW 6 mph 54%
9pm Clear 88º 1% SW 5 mph 60%
10pm Clear 87º 1% WSW 5 mph 62%
11pm Clear 87º 1% WSW 5 mph 62%
Fri
Jul 3 		Mostly Sunny 99º / 78º 21% WNW 11 mph 50%
Sat
Jul 4 		PM Thunderstorms 97º / 74º 67% WNW 10 mph 52%
Sun
Jul 5 		PM Thunderstorms 89º / 70º 86% WNW 7 mph 60%
Mon
Jul 6 		Scattered Thunderstorms 81º / 69º 54% ENE 8 mph 73%
Tue
Jul 7 		Partly Cloudy 81º / 66º 21% NE 9 mph 68%

Weather Radar for Cos Cob Harbor, CT See Radar

See Radar Map

* Playback displays weather for the past 6 hours.

NOAA Weather Marine Forecast for Cos Cob Harbor, CT

Overnight
Low : 71ºF
SW wind around 9 kt. A slight chance of showers and thunderstorms. Seas around 1 ft.
Wednesday
High : 92ºF
SSW wind around 10 kt. A slight chance of showers after 2pm. Seas around 1 ft.
Wednesday Night
Low : 75ºF
SSW wind around 9 kt. A slight chance of showers and thunderstorms before 2am. Seas around 1 ft.
Thursday
High : 99ºF
WSW wind 6 to 9 kt. Sunny. Seas 1 ft or less.
Thursday Night
Low : 79ºF
SW wind 5 to 7 kt becoming W after midnight. Clear. Seas 1 ft or less.
Friday
High : 99ºF
W wind 5 to 9 kt. Sunny. Seas 1 ft or less.
Friday Night
Low : 75ºF
WNW wind around 6 kt becoming variable and less than 5 kt after midnight. Mostly clear. Seas 1 ft or less.
Independence Day
High : 95ºF
Variable winds less than 5 kt becoming W 5 to 8 kt in the afternoon. A chance of showers and thunderstorms after 2pm. Seas 1 ft or less.
Saturday Night
Low : 72ºF
Variable winds 5 kt or less. A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Seas 1 ft or less.

NOAA Buoy Data Near Cos Cob Harbor, CT See Map

Loading Map...
Loading Buoy Data...

    Wind Speed Forecast for Cos Cob Harbor, CT

    WednesdayThursdayFriday
    Wind Speed (MPH) 889997545796
    4am8am12pm4pm8pm12am4am8am12pm4pm8pm12am
    MPH 889997545796
    DIR SWSWSWSWSSWSSWSWWSWWNWWWSWSW

    Current Weather Conditions In Cos Cob Harbor, CT

    As Of: 29 minutes ago

    • 78ºF
    • 78ºF
    • 8mph
    • 0º (SW)
    • 8mph
    • Partly Cloudy
    • 10mi
    • 30.01"
    • 60%
    • 0ºF

    The weather right now in Cos Cob Harbor, CT is Partly Cloudy. The current temperature is 78°F, and the expected high and low for today, Wednesday, July 1, 2026, are -° high temperature and 73°F low temperature. The wind is currently blowing at 8 miles per hour, and coming from the Southwest. The wind is gusting to 8 mph. With the wind and the atmosphere the temperature feels like 78° Fahrenheit. Expected precipitation is 5 percent, with current humidity at 60 percent, and air pressure at 30.01 in. Visibility is 10 nautical miles. There are 4 current weather alert(s).

    Weather Alerts
    Extreme Heat Watch - 2:07pm Tue Jun 30 2026

    ...EXTREME HEAT WARNING NOW IN EFFECT FROM NOON WEDNESDAY TO 9 PM EDT FRIDAY... ...EXTREME HEAT WATCH NOW IN EFFECT FROM FRIDAY EVENING THROUGH SATURDAY EVENING...

    WHAT: For the Extreme Heat Warning, dangerously hot conditions
    with heat index values up to 111 expected. For the Extreme Heat
    Watch, dangerously hot conditions with heat index values up to 101
    possible.

    WHERE: Portions of southern Connecticut, northeast New Jersey,
    and southeast New York.

    WHEN: For the Extreme Heat Warning, from noon Wednesday to 9 PM
    EDT Friday. For the Extreme Heat Watch, from Friday evening
    through Saturday evening.

    IMPACTS: Extreme heat and humidity will significantly increase
    the potential for heat related illnesses, particularly for those
    working or participating in outdoor activities.

    ADDITIONAL DETAILS: This has potential to be a multi-day extreme
    heat event with near record high temperatures and little overnight
    relief. This level of heat can be deadly for those without
    adequate cooling and hydration. Impacts to transportation
    infrastructure and electrical and water systems are also possible.

    PRECAUTIONARY / PREPAREDNESS ACTIONS:

    An Extreme Heat Warning means that the combination of heat and
    humidity is expected to make it feel like it is 105 degrees or
    greater. Take extra precautions if you work or spend time outside.
    When possible, reschedule strenuous activities to early morning or
    evening. Know the signs and symptoms of heat exhaustion and heat
    stroke. Wear light weight and loose fitting clothing when possible,
    and drink plenty of water.

    Seniors and those with chronic health problems or mental health
    conditions are at an increased risk. Homes without air conditioning
    can be much hotter than outdoor temperatures.

    Use air conditioning to stay cool at home or go to a place that has
    air conditioning. If you don't have home air conditioning, continue
    to seek out cool spaces each day as long as it remains hot, and for
    a few days after if your home is still hot. Check on vulnerable
    friends, family members and neighbors.

    To reduce risk during outdoor work, the Occupational Safety and
    Health Administration recommends scheduling frequent rest breaks in
    shaded or air conditioned environments. Anyone overcome by heat
    should be moved to a cool and shaded location. Heat stroke is an
    emergency! In cases of heat stroke call 9 1 1.

    An Extreme Heat Watch means that the combination of heat and
    humidity could create a dangerous situation in which heat illnesses
    are possible. Take extra precautions if you work or spend time
    outside. When possible, reschedule strenuous activities to early
    morning or evening. Know the signs and symptoms of heat exhaustion
    and heat stroke. Wear light weight and loose fitting clothing when
    possible, and drink plenty of water.

    &&

    Extreme Heat Warning - 2:07pm Tue Jun 30 2026

    ...EXTREME HEAT WARNING NOW IN EFFECT FROM NOON WEDNESDAY TO 9 PM EDT FRIDAY... ...EXTREME HEAT WATCH NOW IN EFFECT FROM FRIDAY EVENING THROUGH SATURDAY EVENING...

    WHAT: For the Extreme Heat Warning, dangerously hot conditions
    with heat index values up to 111 expected. For the Extreme Heat
    Watch, dangerously hot conditions with heat index values up to 101
    possible.

    WHERE: Portions of southern Connecticut, northeast New Jersey,
    and southeast New York.

    WHEN: For the Extreme Heat Warning, from noon Wednesday to 9 PM
    EDT Friday. For the Extreme Heat Watch, from Friday evening
    through Saturday evening.

    IMPACTS: Extreme heat and humidity will significantly increase
    the potential for heat related illnesses, particularly for those
    working or participating in outdoor activities.

    ADDITIONAL DETAILS: This has potential to be a multi-day extreme
    heat event with near record high temperatures and little overnight
    relief. This level of heat can be deadly for those without
    adequate cooling and hydration. Impacts to transportation
    infrastructure and electrical and water systems are also possible.

    PRECAUTIONARY / PREPAREDNESS ACTIONS:

    An Extreme Heat Warning means that the combination of heat and
    humidity is expected to make it feel like it is 105 degrees or
    greater. Take extra precautions if you work or spend time outside.
    When possible, reschedule strenuous activities to early morning or
    evening. Know the signs and symptoms of heat exhaustion and heat
    stroke. Wear light weight and loose fitting clothing when possible,
    and drink plenty of water.

    Seniors and those with chronic health problems or mental health
    conditions are at an increased risk. Homes without air conditioning
    can be much hotter than outdoor temperatures.

    Use air conditioning to stay cool at home or go to a place that has
    air conditioning. If you don't have home air conditioning, continue
    to seek out cool spaces each day as long as it remains hot, and for
    a few days after if your home is still hot. Check on vulnerable
    friends, family members and neighbors.

    To reduce risk during outdoor work, the Occupational Safety and
    Health Administration recommends scheduling frequent rest breaks in
    shaded or air conditioned environments. Anyone overcome by heat
    should be moved to a cool and shaded location. Heat stroke is an
    emergency! In cases of heat stroke call 9 1 1.

    An Extreme Heat Watch means that the combination of heat and
    humidity could create a dangerous situation in which heat illnesses
    are possible. Take extra precautions if you work or spend time
    outside. When possible, reschedule strenuous activities to early
    morning or evening. Know the signs and symptoms of heat exhaustion
    and heat stroke. Wear light weight and loose fitting clothing when
    possible, and drink plenty of water.

    &&

    Air Quality Alert - 11:02pm Tue Jun 30 2026

    ...AIR QUALITY ALERT IN EFFECT FROM 11 AM TO 11 PM EDT WEDNESDAY...

    The Connecticut Department of Energy and Environmental Protection
    has issued an Air Quality Action Day for the following counties:

    Fairfield, New Haven, Middlesex.

    from 11 AM to 11 PM EDT Wednesday.

    An Air Quality Action Day means that Ground Level Ozone within the
    region may approach or exceed unhealthy standards. For additional
    information, please visit the Connecticut Department of Energy and
    Environmental Protection Web site at http://www.ct.gov/deep/aqi

    Small Craft Advisory - 5:42am Tue Jun 30 2026

    ...SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM 2 PM THIS AFTERNOON TO MIDNIGHT EDT TONIGHT...

    WHAT: South winds 10 to 20 kt with gusts between 25 and 30
    knots. Seas 3 to 5 feet expected on ocean waters west of Fire
    island Inlet and 2 to 3 feet on western Long Island Sound.

    WHERE: Long Island Sound west of Port Jefferson and New
    Haven, New York Harbor, South Shore Bays from Jones Inlet
    through Shinnecock Bay, and Sandy Hook NJ to Fire Island Inlet
    NY out 20 NM.

    WHEN: From 2 PM this afternoon to midnight EDT tonight.

    IMPACTS: Conditions will be hazardous to small craft.

    PRECAUTIONARY / PREPAREDNESS ACTIONS:

    Inexperienced mariners, especially those operating smaller
    vessels, should avoid navigating in hazardous conditions.

    &&