NWS Forecast for Groton CT

National Weather Service Forecast for: Groton CT
Issued by: National Weather Service New York, NY

Updated: 2:24 am EDT Jun 30, 2026

Overnight Partly Cloudy	Tuesday Mostly Sunny	Tuesday Night Slight Chance T-storms	Wednesday Mostly Sunny then Slight Chance T-storms	Wednesday Night Partly Cloudy	Thursday Sunny	Thursday Night Clear	Friday Sunny	Friday Night Mostly Clear
Lo 65 °F	Hi 79 °F	Lo 67 °F	Hi 82 °F	Lo 69 °F	Hi 86 °F	Lo 72 °F	Hi 89 °F	Lo 72 °F

Hazardous Weather Outlook
Extreme Heat Watch

Overnight	Partly cloudy, with a steady temperature around 65. Calm wind.
Tuesday	Mostly sunny, with a high near 79. Light southwest wind becoming south 8 to 13 mph in the morning.
Tuesday Night	A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Southwest wind 8 to 10 mph, with gusts as high as 20 mph.
Wednesday	A 20 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 82. Southwest wind 11 to 14 mph.
Wednesday Night	Partly cloudy, with a low around 69. Southwest wind 8 to 11 mph.
Thursday	Sunny, with a high near 86.
Thursday Night	Clear, with a low around 72.
Friday	Sunny, with a high near 89.
Friday Night	Mostly clear, with a low around 72.
Independence Day	A 30 percent chance of showers after 2pm. Mostly sunny, with a high near 93.
Saturday Night	A 30 percent chance of showers. Partly cloudy, with a low around 69.
Sunday	Mostly sunny, with a high near 90.
Sunday Night	A 30 percent chance of showers. Partly cloudy, with a low around 67.
Monday	A 30 percent chance of showers. Partly sunny, with a high near 85.

Forecast from NOAA-NWS for Groton CT.