National Weather Service Forecast for: Janesville WI
Issued by: National Weather Service Milwaukee, WI
Updated: 8:12 pm CST Dec 17, 2025
 
Tonight

Tonight: Rain likely, mainly after 4am. Cloudy, with a temperature rising to around 40 by 5am. Breezy, with a south wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Mostly Cloudy
then Rain
Likely and
Breezy
 Thursday

Thursday: Rain before 2pm, then a slight chance of rain and snow showers between 2pm and 3pm, then snow showers likely after 3pm. Temperature falling to around 29 by 5pm. Breezy, with a south wind 15 to 20 mph becoming west in the afternoon. Winds could gust as high as 35 mph. Chance of precipitation is 100%. New snow accumulation of less than a half inch possible.
Breezy. Rain
then
Rain/Snow
Likely
 Thursday
Night
Thursday Night: Snow showers likely, mainly before 9pm. Mostly cloudy, with a low around 8. Wind chill values between -10 and zero. Breezy, with a west wind around 20 mph, with gusts as high as 35 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Breezy. Snow
Showers
Likely then
Mostly Cloudy
 Friday

Friday: Mostly sunny, with a high near 24. Wind chill values between -10 and zero. Northwest wind 10 to 15 mph becoming south in the afternoon. Winds could gust as high as 30 mph.
Mostly Sunny

 Friday
Night
Friday Night: Mostly cloudy, with a temperature falling to near 19 by 8pm, then rising to around 29 during the remainder of the night. South wind 10 to 15 mph.
Mostly Cloudy

 Saturday

Saturday: A slight chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 38. South wind 10 to 15 mph becoming northwest in the afternoon. Chance of precipitation is 20%.
Slight Chance
Rain/Snow
then Slight
Chance Snow
 Saturday
Night
Saturday Night: Mostly clear, with a low around 10. West wind around 10 mph.
Mostly Clear

 Sunday

Sunday: Sunny, with a high near 24. West wind 5 to 10 mph.
Sunny

 Sunday
Night
Sunday Night: Increasing clouds, with a steady temperature around 19.
Increasing
Clouds
Lo 32 °F⇑ Hi 42 °F⇓ Lo 8 °F Hi 24 °F Lo 19 °F⇑ Hi 38 °F Lo 10 °F Hi 24 °F Lo 19 °F

 

Tonight
 
 Rain likely, mainly after 4am. Cloudy, with a temperature rising to around 40 by 5am. Breezy, with a south wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Thursday
 
 Rain before 2pm, then a slight chance of rain and snow showers between 2pm and 3pm, then snow showers likely after 3pm. Temperature falling to around 29 by 5pm. Breezy, with a south wind 15 to 20 mph becoming west in the afternoon. Winds could gust as high as 35 mph. Chance of precipitation is 100%. New snow accumulation of less than a half inch possible.
Thursday Night
 
 Snow showers likely, mainly before 9pm. Mostly cloudy, with a low around 8. Wind chill values between -10 and zero. Breezy, with a west wind around 20 mph, with gusts as high as 35 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Friday
 
 Mostly sunny, with a high near 24. Wind chill values between -10 and zero. Northwest wind 10 to 15 mph becoming south in the afternoon. Winds could gust as high as 30 mph.
Friday Night
 
 Mostly cloudy, with a temperature falling to near 19 by 8pm, then rising to around 29 during the remainder of the night. South wind 10 to 15 mph.
Saturday
 
 A slight chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 38. South wind 10 to 15 mph becoming northwest in the afternoon. Chance of precipitation is 20%.
Saturday Night
 
 Mostly clear, with a low around 10. West wind around 10 mph.
Sunday
 
 Sunny, with a high near 24. West wind 5 to 10 mph.
Sunday Night
 
 Increasing clouds, with a steady temperature around 19.
Monday
 
 Mostly cloudy, with a high near 35.
Monday Night
 
 Mostly cloudy, with a low around 28.
Tuesday
 
 Partly sunny, with a high near 41.
Tuesday Night
 
 Mostly cloudy, with a low around 24.
Wednesday
 
 Partly sunny, with a high near 37.

 

Forecast from NOAA-NWS for Janesville WI.