National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Groton / New London, Groton / New London Airport (KGON)

Lat: 41.33°NLon: 72.05°WElev: 10ft.

Fair

75°F

24°C

Humidity 100%
Wind Speed S 12 mph
Barometer 30.04 in (1017.1 mb)
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Last update 15 Jul 5:56 pm EDT
Extended Forecast for

South Lyme CT

Heat Advisory July 16, 11:00am until July 17, 10:00pm
Click here for hazard details and duration
Heat Advisory

  • Tonight

    Tonight: Patchy fog after 11pm. Otherwise, increasing clouds, with a low around 70. Light and variable wind.

    Low: 70 °F

    Patchy Fog

  • Wednesday

    Wednesday: Patchy fog before 9am. Otherwise, mostly sunny, with a high near 87. Heat index values as high as 99. Calm wind becoming south 5 to 7 mph in the afternoon.

    High: 87 °F

    Patchy Fog
    then Mostly
    Sunny

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms, mainly after 2am. Increasing clouds, with a low around 72. South wind around 5 mph becoming calm in the evening.

    Low: 72 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Thursday

    Thursday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2pm. Mostly cloudy, with a high near 85. Heat index values as high as 97. Southwest wind 5 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 85 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 8pm. Partly cloudy, with a low around 73. Southwest wind 3 to 6 mph. Chance of precipitation is 60%.

    Low: 73 °F

    Showers
    Likely then
    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 88.

    High: 88 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 64.

    Low: 64 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 82.

    High: 82 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 67.

    Low: 67 °F

    Partly Cloudy

Detailed Forecast

Tonight
Patchy fog after 11pm. Otherwise, increasing clouds, with a low around 70. Light and variable wind.
Wednesday
Patchy fog before 9am. Otherwise, mostly sunny, with a high near 87. Heat index values as high as 99. Calm wind becoming south 5 to 7 mph in the afternoon.
Wednesday Night
A 40 percent chance of showers and thunderstorms, mainly after 2am. Increasing clouds, with a low around 72. South wind around 5 mph becoming calm in the evening.
Thursday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2pm. Mostly cloudy, with a high near 85. Heat index values as high as 97. Southwest wind 5 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
Showers likely and possibly a thunderstorm before 8pm. Partly cloudy, with a low around 73. Southwest wind 3 to 6 mph. Chance of precipitation is 60%.
Friday
Sunny, with a high near 88.
Friday Night
Mostly clear, with a low around 64.
Saturday
Sunny, with a high near 82.
Saturday Night
Partly cloudy, with a low around 67.
Sunday
A 40 percent chance of showers. Partly sunny, with a high near 83.
Sunday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 67.
Monday
Mostly sunny, with a high near 85.
Monday Night
Partly cloudy, with a low around 65.
Tuesday
Mostly sunny, with a high near 82.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
South Lyme CT
 41.33°N 72.32°W (Elev. 56 ft)
Last Update:
3:16 pm EDT Jul 15, 2025
Forecast Valid:
6pm EDT Jul 15, 2025-6pm EDT Jul 22, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation