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

68°F

20°C

Humidity 76%
Wind Speed S 5 mph
Barometer 30.06 in (1017.8 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Last update 25 Jun 7:56 am EDT
Extended Forecast for

Old Lyme CT

  • Today

    Today: Sunny, with a high near 80. Calm wind becoming south around 6 mph in the afternoon.

    High: 80 °F

    Sunny

  • Tonight

    Tonight: A chance of showers and thunderstorms between 2am and 5am, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 62. Light south wind. Chance of precipitation is 60%.

    Low: 62 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers likely and possibly a thunderstorm before 11am, then a slight chance of showers between 11am and 2pm, then a slight chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 78. Southwest wind 3 to 7 mph. Chance of precipitation is 60%.

    High: 78 °F

    Showers
    Likely then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: A slight chance of thunderstorms before 8pm, then a chance of showers after 2am. Mostly cloudy, with a low around 63. Calm wind. Chance of precipitation is 40%.

    Low: 63 °F

    Mostly Cloudy
    then Chance
    Showers

  • Saturday

    Saturday: A 50 percent chance of showers. Mostly cloudy, with a high near 78. Light and variable wind.

    High: 78 °F

    Chance
    Showers

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 62.

    Low: 62 °F

    Mostly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 85.

    High: 85 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 63.

    Low: 63 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 84.

    High: 84 °F

    Sunny

Detailed Forecast

Today
Sunny, with a high near 80. Calm wind becoming south around 6 mph in the afternoon.
Tonight
A chance of showers and thunderstorms between 2am and 5am, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 62. Light south wind. Chance of precipitation is 60%.
Friday
Showers likely and possibly a thunderstorm before 11am, then a slight chance of showers between 11am and 2pm, then a slight chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 78. Southwest wind 3 to 7 mph. Chance of precipitation is 60%.
Friday Night
A slight chance of thunderstorms before 8pm, then a chance of showers after 2am. Mostly cloudy, with a low around 63. Calm wind. Chance of precipitation is 40%.
Saturday
A 50 percent chance of showers. Mostly cloudy, with a high near 78. Light and variable wind.
Saturday Night
Mostly cloudy, with a low around 62.
Sunday
Mostly sunny, with a high near 85.
Sunday Night
Mostly clear, with a low around 63.
Monday
Sunny, with a high near 84.
Monday Night
Partly cloudy, with a low around 65.
Tuesday
Mostly sunny, with a high near 86.
Tuesday Night
A 30 percent chance of showers. Partly cloudy, with a low around 67.
Wednesday
Mostly sunny, with a high near 88.
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ABOUT THIS FORECAST

 
Point Forecast:
Old Lyme CT
 41.31°N 72.36°W (Elev. 30 ft)
Last Update:
2:24 am EDT Jun 25, 2026
Forecast Valid:
8am EDT Jun 25, 2026-6pm EDT Jul 1, 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