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

76°F

24°C

Humidity 82%
Wind Speed W 6 mph
Barometer 29.89 in (1012.1 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index77°F (25°C)
Last update 19 Aug 8:56 am EDT
Extended Forecast for

Old Lyme CT

  • Today

    Today: Sunny, with a high near 83. Calm wind becoming southwest 5 to 7 mph in the afternoon.

    High: 83 °F

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 68. Light south wind.

    Low: 68 °F

    Partly Cloudy

  • Thursday

    Thursday: Showers likely, mainly after 5pm. Increasing clouds, with a high near 81. Calm wind becoming west around 5 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    High: 81 °F

    Mostly Sunny
    then Showers
    Likely

  • Thursday Night

    Thursday Night: Showers likely, mainly before 8pm. Cloudy during the early evening, then gradual clearing, with a low around 62. Calm wind. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 62 °F

    Showers
    Likely then
    Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 80. Light and variable wind becoming northeast around 5 mph in the morning.

    High: 80 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 61.

    Low: 61 °F

    Partly Cloudy

  • Saturday

    Saturday: A 50 percent chance of showers after 8am. Partly sunny, with a high near 77.

    High: 77 °F

    Chance
    Showers

  • Saturday Night

    Saturday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 63.

    Low: 63 °F

    Chance
    Showers

  • Sunday

    Sunday: A 40 percent chance of showers. Partly sunny, with a high near 80.

    High: 80 °F

    Chance
    Showers

Detailed Forecast

Today
Sunny, with a high near 83. Calm wind becoming southwest 5 to 7 mph in the afternoon.
Tonight
Partly cloudy, with a low around 68. Light south wind.
Thursday
Showers likely, mainly after 5pm. Increasing clouds, with a high near 81. Calm wind becoming west around 5 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Thursday Night
Showers likely, mainly before 8pm. Cloudy during the early evening, then gradual clearing, with a low around 62. Calm wind. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday
Mostly sunny, with a high near 80. Light and variable wind becoming northeast around 5 mph in the morning.
Friday Night
Partly cloudy, with a low around 61.
Saturday
A 50 percent chance of showers after 8am. Partly sunny, with a high near 77.
Saturday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 63.
Sunday
A 40 percent chance of showers. Partly sunny, with a high near 80.
Sunday Night
Mostly cloudy, with a low around 63.
Monday
Mostly sunny, with a high near 81.
Monday Night
Mostly clear, with a low around 60.
Tuesday
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 72.36°W (Elev. 30 ft)
Last Update:
5:30 am EDT Aug 19, 2026
Forecast Valid:
9am EDT Aug 19, 2026-6pm EDT Aug 25, 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