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

70°F

21°C

Humidity 93%
Wind Speed Calm
Barometer 29.90 in (1012.5 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Last update 19 Aug 10:56 pm EDT
Extended Forecast for

Old Lyme CT

  • Tonight

    Tonight: Mostly clear, with a low around 67. Calm wind.

    Low: 67 °F

    Mostly Clear

  • Thursday

    Thursday: A 20 percent chance of showers after 11am. Increasing clouds, with a high near 83. Calm wind becoming southwest around 5 mph.

    High: 83 °F

    Slight Chance
    Showers

  • Thursday Night

    Thursday Night: A 50 percent chance of showers, mainly before 5am. Mostly cloudy, with a low around 62. Calm wind.

    Low: 62 °F

    Chance
    Showers

  • Friday

    Friday: A 40 percent chance of showers, mainly after 8am. Partly sunny, with a high near 80. East wind 3 to 6 mph.

    High: 80 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 62. Calm wind.

    Low: 62 °F

    Chance
    Showers

  • Saturday

    Saturday: Showers likely. Mostly cloudy, with a high near 79. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

    High: 79 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: Showers likely. Mostly cloudy, with a low around 64. Chance of precipitation is 60%.

    Low: 64 °F

    Showers
    Likely

  • Sunday

    Sunday: A 40 percent chance of showers. Partly sunny, with a high near 81.

    High: 81 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 63.

    Low: 63 °F

    Partly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 67. Calm wind.
Thursday
A 20 percent chance of showers after 11am. Increasing clouds, with a high near 83. Calm wind becoming southwest around 5 mph.
Thursday Night
A 50 percent chance of showers, mainly before 5am. Mostly cloudy, with a low around 62. Calm wind.
Friday
A 40 percent chance of showers, mainly after 8am. Partly sunny, with a high near 80. East wind 3 to 6 mph.
Friday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 62. Calm wind.
Saturday
Showers likely. Mostly cloudy, with a high near 79. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Saturday Night
Showers likely. Mostly cloudy, with a low around 64. Chance of precipitation is 60%.
Sunday
A 40 percent chance of showers. Partly sunny, with a high near 81.
Sunday Night
Partly cloudy, with a low around 63.
Monday
Sunny, with a high near 81.
Monday Night
Mostly clear, with a low around 59.
Tuesday
Sunny, with a high near 80.
Tuesday Night
Mostly clear, with a low around 60.
Wednesday
Mostly sunny, with a high near 80.
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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:
2:29 pm EDT Aug 19, 2026
Forecast Valid:
11pm EDT Aug 19, 2026-6pm EDT Aug 26, 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