National Weather Service Forecast for: Summerville SC
Issued by: National Weather Service Charleston, SC
Updated: 3:06 am EDT Aug 20, 2026
 
Today

Today: A 30 percent chance of showers and thunderstorms, mainly between 2pm and 5pm. Sunny, with a high near 95. Heat index values as high as 108. Calm wind becoming southeast around 5 mph in the afternoon.
Sunny then
Chance
T-storms
 Tonight

Tonight: Mostly clear, with a low around 76. South wind around 6 mph becoming calm in the evening.
Mostly Clear

 Friday

Friday: Showers and thunderstorms likely, mainly after 5pm. Increasing clouds, with a high near 95. Heat index values as high as 109. Calm wind becoming south 5 to 9 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Sunny then
T-storms
Likely
 Friday
Night
Friday Night: A 50 percent chance of showers and thunderstorms. Cloudy, then gradually becoming partly cloudy, with a low around 74. South wind around 6 mph becoming calm in the evening. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Chance
T-storms

 Saturday

Saturday: Showers and thunderstorms likely, mainly after 2pm. Partly sunny, with a high near 93. Calm wind becoming southwest around 6 mph in the afternoon. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Slight Chance
T-storms then
T-storms
Likely
 Saturday
Night
Saturday Night: Showers and thunderstorms likely, mainly before 8pm. Partly cloudy, with a low around 73. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
T-storms
Likely then
Chance
T-storms
 Sunday

Sunday: A 20 percent chance of showers and thunderstorms after 2pm. Sunny, with a high near 94.
Sunny then
Slight Chance
T-storms
 Sunday
Night
Sunday Night: Mostly clear, with a low around 73.
Mostly Clear

 Monday

Monday: A 20 percent chance of showers and thunderstorms after 2pm. Sunny, with a high near 93.
Sunny then
Slight Chance
T-storms
Hi 95 °F Lo 76 °F Hi 95 °F Lo 74 °F Hi 93 °F Lo 73 °F Hi 94 °F Lo 73 °F Hi 93 °F

 

Today
 
 A 30 percent chance of showers and thunderstorms, mainly between 2pm and 5pm. Sunny, with a high near 95. Heat index values as high as 108. Calm wind becoming southeast around 5 mph in the afternoon.
Tonight
 
 Mostly clear, with a low around 76. South wind around 6 mph becoming calm in the evening.
Friday
 
 Showers and thunderstorms likely, mainly after 5pm. Increasing clouds, with a high near 95. Heat index values as high as 109. Calm wind becoming south 5 to 9 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Friday Night
 
 A 50 percent chance of showers and thunderstorms. Cloudy, then gradually becoming partly cloudy, with a low around 74. South wind around 6 mph becoming calm in the evening. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday
 
 Showers and thunderstorms likely, mainly after 2pm. Partly sunny, with a high near 93. Calm wind becoming southwest around 6 mph in the afternoon. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday Night
 
 Showers and thunderstorms likely, mainly before 8pm. Partly cloudy, with a low around 73. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday
 
 A 20 percent chance of showers and thunderstorms after 2pm. Sunny, with a high near 94.
Sunday Night
 
 Mostly clear, with a low around 73.
Monday
 
 A 20 percent chance of showers and thunderstorms after 2pm. Sunny, with a high near 93.
Monday Night
 
 Mostly clear, with a low around 73.
Tuesday
 
 A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 92.
Tuesday Night
 
 A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 73.
Wednesday
 
 A 50 percent chance of showers and thunderstorms. Sunny, with a high near 92.

 

Forecast from NOAA-NWS for Summerville SC.