National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Groton / New London, Groton / New London Airport (KGON)

Lat: 41.33°NLon: 72.05°WElev: 10ft.

Thunderstorm Heavy Rain Fog/Mist

65°F

18°C

Humidity 97%
Wind Speed SE 8 mph
Barometer 29.88 in (1011.8 mb)
Dewpoint 64°F (18°C)
Visibility 1.00 mi
Last update 23 Jun 1:56 am EDT
Extended Forecast for

Old Lyme CT

Flood Advisory until June 23, 05:15am
Click here for hazard details and duration
Flood Advisory
  •  
    Flood Advisory until June 23, 05:15am

    NOW until 5:15am Tue

    Flood Advisory

  • Overnight

    Low: 66 °F

    Showers

  • Tuesday

    Tuesday: Showers and possibly a thunderstorm. High near 73. South wind 5 to 7 mph becoming northwest in the afternoon. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 73 °F

    Showers

  • Tuesday Night

    Tuesday Night: Showers likely, mainly before 8pm. Cloudy, then gradually becoming partly cloudy, with a low around 61. North wind 3 to 6 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 61 °F

    Showers
    Likely then
    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 81. West wind 3 to 7 mph.

    High: 81 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 62. Calm wind.

    Low: 62 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 80.

    High: 80 °F

    Sunny

  • Thursday Night

    Thursday Night: A 50 percent chance of showers after 2am. Partly cloudy, with a low around 63.

    Low: 63 °F

    Partly Cloudy
    then Chance
    Showers

  • Friday

    Friday: A 40 percent chance of showers before 2pm. Partly sunny, with a high near 78.

    High: 78 °F

    Chance
    Showers

Detailed Forecast

Overnight
Showers and possibly a thunderstorm. Steady temperature around 66. South wind around 7 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday
Showers and possibly a thunderstorm. High near 73. South wind 5 to 7 mph becoming northwest in the afternoon. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
Tuesday Night
Showers likely, mainly before 8pm. Cloudy, then gradually becoming partly cloudy, with a low around 61. North wind 3 to 6 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Wednesday
Sunny, with a high near 81. West wind 3 to 7 mph.
Wednesday Night
Mostly clear, with a low around 62. Calm wind.
Thursday
Sunny, with a high near 80.
Thursday Night
A 50 percent chance of showers after 2am. Partly cloudy, with a low around 63.
Friday
A 40 percent chance of showers before 2pm. Partly sunny, with a high near 78.
Friday Night
A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 64.
Saturday
A 50 percent chance of showers. Partly sunny, with a high near 77.
Saturday Night
A 30 percent chance of showers. Partly cloudy, with a low around 63.
Sunday
Mostly sunny, with a high near 80.
Sunday Night
Mostly clear, with a low around 63.
Monday
Mostly sunny, with a high near 81.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Old Lyme CT
 41.29°N 72.33°W (Elev. 16 ft)
Last Update:
8:23 pm EDT Jun 22, 2026
Forecast Valid:
2am EDT Jun 23, 2026-6pm EDT Jun 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