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

49°F

9°C

Humidity 90%
Wind Speed S 3 mph
Barometer 30.09 in (1018.8 mb)
Dewpoint 46°F (8°C)
Visibility 10.00 mi
Last update 13 May 3:56 am EDT
Extended Forecast for

Old Lyme CT

  • Today

    Today: A slight chance of showers between 8am and 11am. Mostly cloudy, with a high near 66. Light south wind increasing to 11 to 16 mph in the morning. Winds could gust as high as 31 mph. Chance of precipitation is 20%.

    High: 66 °F

    Slight Chance
    Showers then
    Mostly Cloudy

  • Tonight

    Tonight: A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 52. Southeast wind 5 to 9 mph, with gusts as high as 25 mph.

    Low: 52 °F

    Mostly Cloudy
    then Chance
    Showers

  • Thursday

    Thursday: Showers, with thunderstorms also possible after 2pm. High near 65. East wind around 6 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 65 °F

    Showers

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 51. Calm wind. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 51 °F

    Showers
    Likely

  • Friday

    Friday: Showers likely, mainly between 8am and 2pm. Mostly cloudy, with a high near 67. Calm wind becoming north around 6 mph in the afternoon. Chance of precipitation is 70%.

    High: 67 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 51.

    Low: 51 °F

    Chance
    Showers then
    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 75.

    High: 75 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 56.

    Low: 56 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

Detailed Forecast

Today
A slight chance of showers between 8am and 11am. Mostly cloudy, with a high near 66. Light south wind increasing to 11 to 16 mph in the morning. Winds could gust as high as 31 mph. Chance of precipitation is 20%.
Tonight
A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 52. Southeast wind 5 to 9 mph, with gusts as high as 25 mph.
Thursday
Showers, with thunderstorms also possible after 2pm. High near 65. East wind around 6 mph. Chance of precipitation is 80%. 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. Mostly cloudy, with a low around 51. Calm wind. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday
Showers likely, mainly between 8am and 2pm. Mostly cloudy, with a high near 67. Calm wind becoming north around 6 mph in the afternoon. Chance of precipitation is 70%.
Friday Night
A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 51.
Saturday
Sunny, with a high near 75.
Saturday Night
Mostly clear, with a low around 56.
Sunday
Sunny, with a high near 81.
Sunday Night
Partly cloudy, with a low around 56.
Monday
Mostly sunny, with a high near 78.
Monday Night
Partly cloudy, with a low around 56.
Tuesday
Mostly sunny, with a high near 79.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Old Lyme CT
 41.31°N 72.33°W (Elev. 43 ft)
Last Update:
2:29 am EDT May 13, 2026
Forecast Valid:
4am EDT May 13, 2026-6pm EDT May 19, 2026
 
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