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.

Fog/Mist

69°F

21°C

Humidity 96%
Wind Speed NE 3 mph
Barometer 29.98 in (1015.1 mb)
Dewpoint 68°F (20°C)
Visibility 2.50 mi
Last update 22 Aug 5:56 pm EDT
Extended Forecast for

Old Lyme CT

  • Tonight

    Tonight: Patchy drizzle before 11pm, then a chance of showers and thunderstorms, mainly after 2am. Patchy fog after 8pm. Otherwise, mostly cloudy, with a low around 63. Calm wind. Chance of precipitation is 50%.

    Low: 63 °F

    Chance
    Showers and
    Patchy Fog

  • Sunday

    Sunday: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80. East wind 5 to 8 mph becoming south in the afternoon.

    High: 80 °F

    Chance
    Showers then
    Chance
    T-storms

  • Sunday Night

    Sunday Night: A chance of thunderstorms before 8pm. Mostly cloudy, then gradually becoming clear, with a low around 63. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 30%.

    Low: 63 °F

    Chance
    T-storms then
    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 80. Calm wind becoming southwest 5 to 9 mph in the morning.

    High: 80 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 59. Light west wind.

    Low: 59 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 79.

    High: 79 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 60.

    Low: 60 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

  • Wednesday Night

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

    Low: 63 °F

    Mostly Clear

Detailed Forecast

Tonight
Patchy drizzle before 11pm, then a chance of showers and thunderstorms, mainly after 2am. Patchy fog after 8pm. Otherwise, mostly cloudy, with a low around 63. Calm wind. Chance of precipitation is 50%.
Sunday
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80. East wind 5 to 8 mph becoming south in the afternoon.
Sunday Night
A chance of thunderstorms before 8pm. Mostly cloudy, then gradually becoming clear, with a low around 63. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 30%.
Monday
Sunny, with a high near 80. Calm wind becoming southwest 5 to 9 mph in the morning.
Monday Night
Mostly clear, with a low around 59. Light west wind.
Tuesday
Sunny, with a high near 79.
Tuesday Night
Mostly clear, with a low around 60.
Wednesday
Sunny, with a high near 81.
Wednesday Night
Mostly clear, with a low around 63.
Thursday
Mostly sunny, with a high near 81.
Thursday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 65.
Friday
A 40 percent chance of showers. Partly sunny, with a high near 81.
Friday Night
Partly cloudy, with a low around 64.
Saturday
Mostly sunny, with a high near 82.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Old Lyme CT
 41.31°N 72.33°W (Elev. 43 ft)
Last Update:
2:45 pm EDT Aug 22, 2026
Forecast Valid:
6pm EDT Aug 22, 2026-6pm EDT Aug 29, 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