National Weather Service Forecast for: Bay St. Louis MS
Issued by: National Weather Service New Orleans/Baton Rouge, LA
Updated: 5:11 am CDT May 26, 2026
 
Today

Today: Showers and thunderstorms likely, mainly before 4pm, then showers likely and possibly a thunderstorm after 4pm. Increasing clouds, with a high near 80. South wind 5 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between three quarters and one inch possible.
Showers
Likely then
T-storms
Likely
 Tonight

Tonight: A chance of showers and thunderstorms before 3am, then a chance of showers between 3am and 4am, then a chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 78. South wind around 10 mph. Chance of precipitation is 30%.
Chance
T-storms then
Chance
Showers
 Wednesday

Wednesday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 82. Southeast wind around 10 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Chance
T-storms then
Showers
Likely
 Wednesday
Night
Wednesday Night: A chance of showers and thunderstorms before 1am, then showers likely between 1am and 4am, then showers likely and possibly a thunderstorm after 4am. Mostly cloudy, with a low around 77. Southeast wind 5 to 10 mph. Chance of precipitation is 60%.
Chance
Showers then
Showers
Likely
 Thursday

Thursday: Showers and possibly a thunderstorm. High near 80. South wind 5 to 10 mph. Chance of precipitation is 90%.
Showers

 Thursday
Night
Thursday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 76. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.
Chance
T-storms then
Showers
Likely
 Friday

Friday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 81. Light south wind increasing to 5 to 10 mph in the afternoon. Chance of precipitation is 70%.
Showers
Likely

 Friday
Night
Friday Night: A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75. South wind around 5 mph becoming west after midnight.
Chance
T-storms

 Saturday

Saturday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly sunny, with a high near 83. West wind 5 to 10 mph becoming southwest in the afternoon.
Chance
T-storms then
Showers
Likely
Hi 80 °F Lo 78 °F Hi 82 °F Lo 77 °F Hi 80 °F Lo 76 °F Hi 81 °F Lo 75 °F Hi 83 °F

Flood Watch
 

Today
 
 Showers and thunderstorms likely, mainly before 4pm, then showers likely and possibly a thunderstorm after 4pm. Increasing clouds, with a high near 80. South wind 5 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between three quarters and one inch possible.
Tonight
 
 A chance of showers and thunderstorms before 3am, then a chance of showers between 3am and 4am, then a chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 78. South wind around 10 mph. Chance of precipitation is 30%.
Wednesday
 
 A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 82. Southeast wind around 10 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Wednesday Night
 
 A chance of showers and thunderstorms before 1am, then showers likely between 1am and 4am, then showers likely and possibly a thunderstorm after 4am. Mostly cloudy, with a low around 77. Southeast wind 5 to 10 mph. Chance of precipitation is 60%.
Thursday
 
 Showers and possibly a thunderstorm. High near 80. South wind 5 to 10 mph. Chance of precipitation is 90%.
Thursday Night
 
 A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 76. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.
Friday
 
 Showers likely and possibly a thunderstorm. Partly sunny, with a high near 81. Light south wind increasing to 5 to 10 mph in the afternoon. Chance of precipitation is 70%.
Friday Night
 
 A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75. South wind around 5 mph becoming west after midnight.
Saturday
 
 A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly sunny, with a high near 83. West wind 5 to 10 mph becoming southwest in the afternoon.
Saturday Night
 
 A chance of showers and thunderstorms. Partly cloudy, with a low around 75. Southwest wind around 5 mph becoming west after midnight.
Sunday
 
 A chance of showers and thunderstorms. Partly sunny, with a high near 83. North wind 5 to 10 mph becoming southeast in the afternoon.
Sunday Night
 
 A chance of showers and thunderstorms. Mostly cloudy, with a low around 75. East wind 5 to 10 mph.
Monday
 
 A chance of showers and thunderstorms. Mostly sunny, with a high near 81. Northeast wind around 10 mph.

 

Forecast from NOAA-NWS for Bay St. Louis MS.