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.

Overcast

67°F

19°C

Humidity 93%
Wind Speed SE 12 mph
Barometer 29.90 in (1012.6 mb)
Dewpoint 65°F (18°C)
Visibility 9.00 mi
Last update 17 Aug 8:56 am EDT
Extended Forecast for

Old Lyme CT

  • Today

    Today: Showers likely, mainly before 11am. Patchy fog before 2pm. Otherwise, mostly cloudy, with a high near 79. East wind 6 to 9 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 79 °F

    Showers
    Likely and
    Patchy Fog

  • Tonight

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

    Low: 67 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 85. Light and variable wind.

    High: 85 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 65. Calm wind.

    Low: 65 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 85. Calm wind becoming southwest 5 to 7 mph in the afternoon.

    High: 85 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 67.

    Low: 67 °F

    Mostly Clear

  • Thursday

    Thursday: A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 83.

    High: 83 °F

    Mostly Sunny
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A 30 percent chance of showers before 2am. Partly cloudy, with a low around 62.

    Low: 62 °F

    Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 81.

    High: 81 °F

    Mostly Sunny

Detailed Forecast

Today
Showers likely, mainly before 11am. Patchy fog before 2pm. Otherwise, mostly cloudy, with a high near 79. East wind 6 to 9 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Tonight
Mostly cloudy, with a low around 67. Calm wind.
Tuesday
Mostly sunny, with a high near 85. Light and variable wind.
Tuesday Night
Mostly clear, with a low around 65. Calm wind.
Wednesday
Sunny, with a high near 85. Calm wind becoming southwest 5 to 7 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 67.
Thursday
A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 83.
Thursday Night
A 30 percent chance of showers before 2am. Partly cloudy, with a low around 62.
Friday
Mostly sunny, with a high near 81.
Friday Night
A 30 percent chance of showers after 2am. Partly cloudy, with a low around 62.
Saturday
A 40 percent chance of showers. Partly sunny, with a high near 78.
Saturday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 62.
Sunday
A 50 percent chance of showers. Partly sunny, with a high near 79.
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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:
4:20 am EDT Aug 17, 2026
Forecast Valid:
9am EDT Aug 17, 2026-6pm EDT Aug 23, 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