National Weather Service Forecast for: Janesville WI
Issued by: National Weather Service Milwaukee, WI
Updated: 10:54 pm CDT May 31, 2025
 
Tonight

Tonight: Mostly clear, with a low around 45. Calm wind.
Mostly Clear


 Sunday

Sunday: Mostly sunny, with a high near 77. Calm wind becoming north around 5 mph in the afternoon.
Mostly Sunny


 Sunday
Night
Sunday Night: Partly cloudy, with a low around 56. Northwest wind around 5 mph becoming southeast in the evening.
Partly Cloudy


 Monday

Monday: Sunny, with a high near 87. Southwest wind 5 to 10 mph.
Sunny


 Monday
Night
Monday Night: Partly cloudy, with a low around 67. South wind around 10 mph.
Partly Cloudy


 Tuesday

Tuesday: A chance of showers before 10am, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 84. Breezy, with a south wind 10 to 15 mph increasing to 15 to 20 mph in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Chance
Showers then
Showers
Likely and
Breezy
 Tuesday
Night
Tuesday Night: Showers and possibly a thunderstorm. Low around 60. South wind 10 to 15 mph becoming west after midnight. Chance of precipitation is 80%. New rainfall amounts between 1 and 2 inches possible.
T-storms


 Wednesday

Wednesday: Showers likely, mainly before 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 70. North wind around 10 mph becoming northeast in the afternoon. Chance of precipitation is 60%. New precipitation amounts between a half and three quarters of an inch possible.
Showers
Likely

 Wednesday
Night
Wednesday Night: A 40 percent chance of showers. Increasing clouds, with a low around 54.
Chance
Showers
Lo 45 °F Hi 77 °F Lo 56 °F Hi 87 °F Lo 67 °F Hi 84 °F Lo 60 °F Hi 70 °F Lo 54 °F

 

Tonight
 
 Mostly clear, with a low around 45. Calm wind.
Sunday
 
 Mostly sunny, with a high near 77. Calm wind becoming north around 5 mph in the afternoon.
Sunday Night
 
 Partly cloudy, with a low around 56. Northwest wind around 5 mph becoming southeast in the evening.
Monday
 
 Sunny, with a high near 87. Southwest wind 5 to 10 mph.
Monday Night
 
 Partly cloudy, with a low around 67. South wind around 10 mph.
Tuesday
 
 A chance of showers before 10am, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 84. Breezy, with a south wind 10 to 15 mph increasing to 15 to 20 mph in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night
 
 Showers and possibly a thunderstorm. Low around 60. South wind 10 to 15 mph becoming west after midnight. Chance of precipitation is 80%. New rainfall amounts between 1 and 2 inches possible.
Wednesday
 
 Showers likely, mainly before 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 70. North wind around 10 mph becoming northeast in the afternoon. Chance of precipitation is 60%. New precipitation amounts between a half and three quarters of an inch possible.
Wednesday Night
 
 A 40 percent chance of showers. Increasing clouds, with a low around 54.
Thursday
 
 A chance of showers and thunderstorms. Mostly cloudy, with a high near 70. Chance of precipitation is 40%.
Thursday Night
 
 A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 53.
Friday
 
 A 20 percent chance of showers. Mostly sunny, with a high near 75.
Friday Night
 
 Partly cloudy, with a low around 55.
Saturday
 
 A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 77.

 

Forecast from NOAA-NWS for Janesville WI.