National Weather Service Forecast for: Groton CT
Issued by: National Weather Service New York, NY
Updated: 11:53 pm EDT Jun 21, 2026
 
Today

Today: Showers, mainly after noon. High near 70. Calm wind becoming southeast 5 to 7 mph in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Partly Sunny
then Showers
 Tonight

Tonight: Showers, with thunderstorms also possible after 11pm. Steady temperature around 66. South wind around 11 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New rainfall amounts between three quarters and one inch possible.
Showers

 Tuesday

Tuesday: Showers, mainly before 2pm. High near 72. Southwest wind around 7 mph becoming northwest in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Showers

 Tuesday
Night
Tuesday Night: A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 61. Calm wind becoming northwest around 5 mph after midnight.
Chance
Showers then
Mostly Clear
 Wednesday

Wednesday: Sunny, with a high near 74. West wind 5 to 8 mph.
Sunny

 Wednesday
Night
Wednesday Night: Clear, with a low around 60.
Clear

 Thursday

Thursday: Sunny, with a high near 73.
Sunny

 Thursday
Night
Thursday Night: Partly cloudy, with a low around 64.
Partly Cloudy

 Friday

Friday: A 30 percent chance of showers after 8am. Partly sunny, with a high near 72.
Chance
Showers
Hi 70 °F Lo 66 °F Hi 72 °F Lo 61 °F Hi 74 °F Lo 60 °F Hi 73 °F Lo 64 °F Hi 72 °F

Hazardous Weather Outlook
 

Today
 
 Showers, mainly after noon. High near 70. Calm wind becoming southeast 5 to 7 mph in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Tonight
 
 Showers, with thunderstorms also possible after 11pm. Steady temperature around 66. South wind around 11 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New rainfall amounts between three quarters and one inch possible.
Tuesday
 
 Showers, mainly before 2pm. High near 72. Southwest wind around 7 mph becoming northwest in the afternoon. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Tuesday Night
 
 A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 61. Calm wind becoming northwest around 5 mph after midnight.
Wednesday
 
 Sunny, with a high near 74. West wind 5 to 8 mph.
Wednesday Night
 
 Clear, with a low around 60.
Thursday
 
 Sunny, with a high near 73.
Thursday Night
 
 Partly cloudy, with a low around 64.
Friday
 
 A 30 percent chance of showers after 8am. Partly sunny, with a high near 72.
Friday Night
 
 A 30 percent chance of showers. Mostly cloudy, with a low around 64.
Saturday
 
 Mostly sunny, with a high near 75.
Saturday Night
 
 Partly cloudy, with a low around 63.
Sunday
 
 Sunny, with a high near 75.

 

Forecast from NOAA-NWS for Groton CT.