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

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

Lat: 41.33°NLon: 72.05°WElev: 10ft.

Fair

78°F

26°C

Humidity 82%
Wind Speed SE 10 mph
Barometer 29.96 in (1014.5 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 2 Aug 2:56 pm EDT
Extended Forecast for

South Lyme CT

  • This Afternoon

    This Afternoon: Mostly cloudy, with a high near 83. South wind around 9 mph.

    High: 83 °F

    Mostly Cloudy

  • Tonight

    Tonight: A chance of showers, then showers and possibly a thunderstorm after 11pm. Patchy fog between 8pm and 2am. Low around 70. Light southeast wind becoming south 5 to 9 mph after midnight. Winds could gust as high as 21 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 70 °F

    Showers and
    Patchy Fog

  • Monday

    Monday: Showers and possibly a thunderstorm. High near 81. South wind around 15 mph, with gusts as high as 28 mph. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.

    High: 81 °F

    Showers

  • Monday Night

    Monday Night: Showers and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 11pm. Low around 63. Southwest wind 5 to 7 mph becoming light and variable in the evening. Winds could gust as high as 20 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 63 °F

    Showers then
    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 83. Light and variable wind becoming west around 6 mph in the afternoon.

    High: 83 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 64.

    Low: 64 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 82.

    High: 82 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 69.

    Low: 69 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 85.

    High: 85 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Mostly cloudy, with a high near 83. South wind around 9 mph.
Tonight
A chance of showers, then showers and possibly a thunderstorm after 11pm. Patchy fog between 8pm and 2am. Low around 70. Light southeast wind becoming south 5 to 9 mph after midnight. Winds could gust as high as 21 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday
Showers and possibly a thunderstorm. High near 81. South wind around 15 mph, with gusts as high as 28 mph. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.
Monday Night
Showers and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 11pm. Low around 63. Southwest wind 5 to 7 mph becoming light and variable in the evening. Winds could gust as high as 20 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday
Sunny, with a high near 83. Light and variable wind becoming west around 6 mph in the afternoon.
Tuesday Night
Partly cloudy, with a low around 64.
Wednesday
Mostly sunny, with a high near 82.
Wednesday Night
Mostly cloudy, with a low around 69.
Thursday
Mostly sunny, with a high near 85.
Thursday Night
A chance of showers between 8pm and 2am. Partly cloudy, with a low around 72. Chance of precipitation is 40%.
Friday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 86.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 71.
Saturday
A 30 percent chance of showers. Mostly sunny, with a high near 86.
Saturday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 70.
Sunday
Mostly sunny, with a high near 86.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
South Lyme CT
 41.32°N 72.29°W (Elev. 98 ft)
Last Update:
2:30 pm EDT Aug 2, 2026
Forecast Valid:
3pm EDT Aug 2, 2026-6pm EDT Aug 9, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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