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

34°F

1°C

Humidity 100%
Wind Speed S 3 mph
Barometer 29.96 in (1014.4 mb)
Dewpoint 34°F (1°C)
Visibility 0.75 mi
Last update 9 Mar 1:56 am EDT
Extended Forecast for

Old Lyme CT

  • Overnight

    Overnight: Partly cloudy, with a low around 36. Calm wind.

    Low: 36 °F

    Partly Cloudy

  • Monday

    Monday: Patchy fog between 7am and 9am. Otherwise, mostly sunny, with a high near 58. Calm wind becoming southwest around 6 mph in the afternoon.

    High: 58 °F

    Patchy Fog
    then Sunny

  • Monday Night

    Monday Night: Patchy fog after 2am. Otherwise, partly cloudy, with a low around 37. Calm wind.

    Low: 37 °F

    Partly Cloudy
    then Patchy
    Fog

  • Tuesday

    Tuesday: Patchy fog before 8am. Otherwise, mostly sunny, with a high near 58. Calm wind becoming south around 6 mph in the afternoon.

    High: 58 °F

    Patchy Fog
    then Mostly
    Sunny

  • Tuesday Night

    Tuesday Night: Patchy fog. Otherwise, mostly cloudy, with a low around 38. Calm wind.

    Low: 38 °F

    Patchy Fog

  • Wednesday

    Wednesday: Cloudy, with a high near 54.

    High: 54 °F

    Cloudy

  • Wednesday Night

    Wednesday Night: A 50 percent chance of rain. Mostly cloudy, with a low around 45.

    Low: 45 °F

    Chance Rain

  • Thursday

    Thursday: Rain likely before 2pm, then a chance of rain and snow. Mostly cloudy, with a high near 55. Chance of precipitation is 60%.

    High: 55 °F

    Rain Likely
    then
    Rain/Snow
    Likely

  • Thursday Night

    Thursday Night: A chance of rain and snow before 8pm. Partly cloudy, with a low around 28. Chance of precipitation is 30%.

    Low: 28 °F

    Chance
    Rain/Snow
    then Mostly
    Clear

Detailed Forecast

Overnight
Partly cloudy, with a low around 36. Calm wind.
Monday
Patchy fog between 7am and 9am. Otherwise, mostly sunny, with a high near 58. Calm wind becoming southwest around 6 mph in the afternoon.
Monday Night
Patchy fog after 2am. Otherwise, partly cloudy, with a low around 37. Calm wind.
Tuesday
Patchy fog before 8am. Otherwise, mostly sunny, with a high near 58. Calm wind becoming south around 6 mph in the afternoon.
Tuesday Night
Patchy fog. Otherwise, mostly cloudy, with a low around 38. Calm wind.
Wednesday
Cloudy, with a high near 54.
Wednesday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 45.
Thursday
Rain likely before 2pm, then a chance of rain and snow. Mostly cloudy, with a high near 55. Chance of precipitation is 60%.
Thursday Night
A chance of rain and snow before 8pm. Partly cloudy, with a low around 28. Chance of precipitation is 30%.
Friday
Mostly sunny, with a high near 43.
Friday Night
A chance of rain and snow. Mostly cloudy, with a low around 34. Chance of precipitation is 50%.
Saturday
A 30 percent chance of snow. Mostly sunny, with a high near 47.
Saturday Night
Mostly cloudy, with a low around 30.
Sunday
A 30 percent chance of rain. Mostly cloudy, with a high near 47.
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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:
1:57 am EDT Mar 9, 2026
Forecast Valid:
2am EDT Mar 9, 2026-6pm EDT Mar 15, 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