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

60°F

16°C

Humidity 48%
Wind Speed N 8 mph
Barometer 29.88 in (1011.8 mb)
Dewpoint 40°F (4°C)
Visibility 10.00 mi
Last update 17 Oct 2:56 pm EDT
Extended Forecast for

Old Lyme CT

  • Tonight

    Tonight: Patchy frost after 4am. Otherwise, mostly clear, with a low around 37. Northwest wind 3 to 7 mph.

    Low: 37 °F

    Mostly Clear
    then Patchy
    Frost

  • Saturday

    Saturday: Areas of frost before 8am. Otherwise, sunny, with a high near 64. Light and variable wind becoming west around 5 mph in the afternoon.

    High: 64 °F

    Areas Frost
    then Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 49. Calm wind.

    Low: 49 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 69. South wind 5 to 14 mph.

    High: 69 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Showers, with thunderstorms also possible after 5am. Low around 56. South wind 11 to 13 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 56 °F

    Slight Chance
    Showers then
    Showers

  • Monday

    Monday: Showers, mainly before 2pm. High near 66. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.

    High: 66 °F

    Showers

  • Monday Night

    Monday Night: A 30 percent chance of showers before 2am. Partly cloudy, with a low around 48.

    Low: 48 °F

    Chance
    Showers

  • Tuesday

    Tuesday: Sunny, with a high near 66.

    High: 66 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Showers likely, mainly after 2am. Mostly cloudy, with a low around 51. Chance of precipitation is 60%.

    Low: 51 °F

    Showers
    Likely

Detailed Forecast

Tonight
Patchy frost after 4am. Otherwise, mostly clear, with a low around 37. Northwest wind 3 to 7 mph.
Saturday
Areas of frost before 8am. Otherwise, sunny, with a high near 64. Light and variable wind becoming west around 5 mph in the afternoon.
Saturday Night
Partly cloudy, with a low around 49. Calm wind.
Sunday
Mostly sunny, with a high near 69. South wind 5 to 14 mph.
Sunday Night
Showers, with thunderstorms also possible after 5am. Low around 56. South wind 11 to 13 mph, with gusts as high as 26 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, mainly before 2pm. High near 66. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.
Monday Night
A 30 percent chance of showers before 2am. Partly cloudy, with a low around 48.
Tuesday
Sunny, with a high near 66.
Tuesday Night
Showers likely, mainly after 2am. Mostly cloudy, with a low around 51. Chance of precipitation is 60%.
Wednesday
Showers likely, mainly before 8am. Partly sunny, with a high near 63. Chance of precipitation is 60%.
Wednesday Night
Partly cloudy, with a low around 45.
Thursday
Mostly sunny, with a high near 61.
Thursday Night
Partly cloudy, with a low around 45.
Friday
A 30 percent chance of showers. Partly sunny, with a high near 61.
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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:
2:05 pm EDT Oct 17, 2025
Forecast Valid:
3pm EDT Oct 17, 2025-6pm EDT Oct 24, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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