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

31°F

-1°C

Humidity 59%
Wind Speed W 3 mph
Barometer 30.41 in (1029.7 mb)
Dewpoint 18°F (-8°C)
Visibility 10.00 mi
Last update 15 Mar 3:56 am EDT
Extended Forecast for

Old Lyme CT

  • Today

    Today: Partly sunny, with a high near 44. Calm wind becoming southeast 5 to 9 mph in the afternoon.

    High: 44 °F

    Partly Sunny

  • Tonight

    Tonight: Showers and possibly a thunderstorm, mainly after 5am. Patchy fog after 2am. Low around 37. East wind 6 to 9 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 37 °F

    Partly Cloudy
    then Showers
    and Patchy
    Fog

  • Monday

    Monday: Intermittent showers and thunderstorms. Patchy fog before noon. Otherwise, cloudy, with a high near 57. South wind 15 to 17 mph, with gusts as high as 36 mph. Chance of precipitation is 50%.

    High: 57 °F

    Intermittent
    T-storms and
    Patchy Fog

  • Monday Night

    Monday Night: Periods of showers and possibly a thunderstorm before 2am, then showers likely. Some of the storms could produce heavy rainfall. Low around 37. South wind 15 to 18 mph, with gusts as high as 45 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 37 °F

    Heavy Rain

  • Tuesday

    Tuesday: Showers likely before 8am. Mostly cloudy, then gradually becoming sunny, with a steady temperature around 41. West wind 10 to 14 mph, with gusts as high as 26 mph. Chance of precipitation is 60%.

    High: 41 °F

    Showers
    Likely then
    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 23.

    Low: 23 °F

    Mostly Clear

  • Wednesday

    Wednesday: Increasing clouds, with a high near 38.

    High: 38 °F

    Increasing
    Clouds

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 27.

    Low: 27 °F

    Mostly Cloudy

  • Thursday

    Thursday: Partly sunny, with a high near 44.

    High: 44 °F

    Partly Sunny

Detailed Forecast

Today
Partly sunny, with a high near 44. Calm wind becoming southeast 5 to 9 mph in the afternoon.
Tonight
Showers and possibly a thunderstorm, mainly after 5am. Patchy fog after 2am. Low around 37. East wind 6 to 9 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Monday
Intermittent showers and thunderstorms. Patchy fog before noon. Otherwise, cloudy, with a high near 57. South wind 15 to 17 mph, with gusts as high as 36 mph. Chance of precipitation is 50%.
Monday Night
Periods of showers and possibly a thunderstorm before 2am, then showers likely. Some of the storms could produce heavy rainfall. Low around 37. South wind 15 to 18 mph, with gusts as high as 45 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Tuesday
Showers likely before 8am. Mostly cloudy, then gradually becoming sunny, with a steady temperature around 41. West wind 10 to 14 mph, with gusts as high as 26 mph. Chance of precipitation is 60%.
Tuesday Night
Mostly clear, with a low around 23.
Wednesday
Increasing clouds, with a high near 38.
Wednesday Night
Mostly cloudy, with a low around 27.
Thursday
Partly sunny, with a high near 44.
Thursday Night
Mostly cloudy, with a low around 31.
Friday
Partly sunny, with a high near 48.
Friday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 33.
Saturday
A 50 percent chance of rain. Partly sunny, with a high near 48.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Old Lyme CT
 41.31°N 72.33°W (Elev. 43 ft)
Last Update:
4:56 am EDT Mar 15, 2026
Forecast Valid:
5am EDT Mar 15, 2026-6pm EDT Mar 21, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation