National Weather Service Forecast for: Derby CT
Issued by: National Weather Service New York, NY
Updated: 9:10 pm EDT Sep 12, 2026
 
Overnight

Overnight: Showers likely and possibly a thunderstorm, mainly after 5am. Mostly cloudy, with a low around 64. Calm wind. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Showers
Likely
 Sunday

Sunday: Showers and possibly a thunderstorm before 2pm, then a chance of showers between 2pm and 5pm. Some of the storms could produce heavy rainfall. High near 77. Light and variable wind becoming east around 6 mph in the morning. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Heavy Rain

 Sunday
Night
Sunday Night: A 30 percent chance of showers, mainly after 2am. Increasing clouds, with a low around 62. Light west wind.
Chance
Showers
 Monday

Monday: A 30 percent chance of showers before 8am. Mostly cloudy through mid morning, then gradual clearing, with a high near 73. Northwest wind 10 to 13 mph.
Chance
Showers then
Sunny
 Monday
Night
Monday Night: Clear, with a low around 51. North wind 5 to 7 mph.
Clear

 Tuesday

Tuesday: Sunny, with a high near 71.
Sunny

 Tuesday
Night
Tuesday Night: Partly cloudy, with a low around 54.
Partly Cloudy

 Wednesday

Wednesday: Sunny, with a high near 76.
Sunny

 Wednesday
Night
Wednesday Night: Partly cloudy, with a low around 60.
Partly Cloudy
Lo 64 °F Hi 77 °F Lo 62 °F Hi 73 °F Lo 51 °F Hi 71 °F Lo 54 °F Hi 76 °F Lo 60 °F

Hazardous Weather Outlook
Flood Watch
 

Overnight
 
 Showers likely and possibly a thunderstorm, mainly after 5am. Mostly cloudy, with a low around 64. Calm wind. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday
 
 Showers and possibly a thunderstorm before 2pm, then a chance of showers between 2pm and 5pm. Some of the storms could produce heavy rainfall. High near 77. Light and variable wind becoming east around 6 mph in the morning. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Sunday Night
 
 A 30 percent chance of showers, mainly after 2am. Increasing clouds, with a low around 62. Light west wind.
Monday
 
 A 30 percent chance of showers before 8am. Mostly cloudy through mid morning, then gradual clearing, with a high near 73. Northwest wind 10 to 13 mph.
Monday Night
 
 Clear, with a low around 51. North wind 5 to 7 mph.
Tuesday
 
 Sunny, with a high near 71.
Tuesday Night
 
 Partly cloudy, with a low around 54.
Wednesday
 
 Sunny, with a high near 76.
Wednesday Night
 
 Partly cloudy, with a low around 60.
Thursday
 
 Mostly sunny, with a high near 79.
Thursday Night
 
 Partly cloudy, with a low around 62.
Friday
 
 A 30 percent chance of showers. Partly sunny, with a high near 78.
Friday Night
 
 A 30 percent chance of showers. Mostly cloudy, with a low around 57.
Saturday
 
 Mostly sunny, with a high near 74.

 

Forecast from NOAA-NWS for Derby CT.