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

37°F

3°C

Humidity 41%
Wind Speed SW 14 mph
Barometer 30.08 in (1018.7 mb)
Dewpoint 15°F (-9°C)
Visibility 10.00 mi
Wind Chill28°F (-2°C)
Last update 13 Mar 1:56 pm EDT
Extended Forecast for

Old Lyme CT

  • This Afternoon

    This Afternoon: Mostly cloudy, with a steady temperature around 42. Southwest wind around 9 mph.

    High: 42 °F

    Mostly Cloudy

  • Tonight

    Tonight: A chance of showers between 11pm and 2am. Mostly cloudy, then gradually becoming mostly clear, with a low around 35. South wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 30%.

    Low: 35 °F

    Chance
    Showers

  • Saturday

    Saturday: Sunny, with a high near 48. West wind 14 to 18 mph, with gusts as high as 37 mph.

    High: 48 °F

    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 30. West wind 5 to 10 mph becoming light northwest after midnight. Winds could gust as high as 20 mph.

    Low: 30 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Mostly cloudy, with a high near 45. Calm wind becoming southeast 5 to 8 mph in the afternoon.

    High: 45 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Rain likely after 2am. Mostly cloudy, with a low around 36. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 36 °F

    Mostly Cloudy
    then Rain
    Likely

  • Monday

    Monday: Rain. High near 57. Chance of precipitation is 100%.

    High: 57 °F

    Rain

  • Monday Night

    Monday Night: Rain and possibly a thunderstorm. Low around 36. Chance of precipitation is 100%.

    Low: 36 °F

    Rain

  • Tuesday

    Tuesday: Rain likely before 8am. Mostly sunny, with a high near 46. Chance of precipitation is 60%.

    High: 46 °F

    Rain Likely
    then Mostly
    Sunny

Detailed Forecast

This Afternoon
Mostly cloudy, with a steady temperature around 42. Southwest wind around 9 mph.
Tonight
A chance of showers between 11pm and 2am. Mostly cloudy, then gradually becoming mostly clear, with a low around 35. South wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 30%.
Saturday
Sunny, with a high near 48. West wind 14 to 18 mph, with gusts as high as 37 mph.
Saturday Night
Increasing clouds, with a low around 30. West wind 5 to 10 mph becoming light northwest after midnight. Winds could gust as high as 20 mph.
Sunday
Mostly cloudy, with a high near 45. Calm wind becoming southeast 5 to 8 mph in the afternoon.
Sunday Night
Rain likely after 2am. Mostly cloudy, with a low around 36. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Monday
Rain. High near 57. Chance of precipitation is 100%.
Monday Night
Rain and possibly a thunderstorm. Low around 36. Chance of precipitation is 100%.
Tuesday
Rain likely before 8am. Mostly sunny, with a high near 46. Chance of precipitation is 60%.
Tuesday Night
Mostly clear, with a low around 23.
Wednesday
Mostly sunny, with a high near 39.
Wednesday Night
Mostly cloudy, with a low around 28.
Thursday
Partly sunny, with a high near 44.
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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:
2:26 pm EDT Mar 13, 2026
Forecast Valid:
2pm EDT Mar 13, 2026-6pm EDT Mar 19, 2026
 
Forecast Discussion
 
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Additional Resources

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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