National Weather Service Forecast for: Janesville WI
Issued by: National Weather Service Milwaukee, WI
Updated: 1:46 am CST Dec 5, 2025
 
Overnight

Overnight: Cloudy, with a low around -4. South wind around 10 mph.
Cloudy

 Friday

Friday: A 20 percent chance of snow after 4pm. Increasing clouds, with a high near 26. Wind chill values between -5 and 5. Southwest wind around 10 mph.
Partly Sunny
then Slight
Chance Snow
 Friday
Night
Friday Night: A chance of snow and freezing rain before 11pm, then a slight chance of freezing rain between 11pm and midnight. Cloudy, with a low around 20. Southwest wind 5 to 10 mph becoming northwest after midnight. Chance of precipitation is 50%.
Chance Wintry
Mix then
Mostly Cloudy
 Saturday

Saturday: Mostly sunny, with a high near 23. Northwest wind around 5 mph becoming calm in the afternoon.
Mostly Sunny

 Saturday
Night
Saturday Night: Snow, mainly after midnight. Low around 11. Calm wind becoming north around 5 mph after midnight. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible.
Chance Snow
then Snow
 Sunday

Sunday: A 40 percent chance of snow before noon. Mostly sunny, with a high near 20. North wind 5 to 10 mph.
Chance Snow
then Mostly
Sunny
 Sunday
Night
Sunday Night: Partly cloudy, with a low around -3. North wind around 5 mph becoming calm in the evening.
Partly Cloudy

 Monday

Monday: Mostly cloudy, with a high near 20. Light and variable wind becoming south 5 to 10 mph in the morning.
Mostly Cloudy

 Monday
Night
Monday Night: Snow likely, mainly after midnight. Mostly cloudy, with a temperature falling to near 14 by 8pm, then rising to around 22 during the remainder of the night. Chance of precipitation is 60%.
Snow Likely
Lo -4 °F Hi 26 °F Lo 20 °F Hi 23 °F Lo 11 °F Hi 20 °F Lo -3 °F Hi 20 °F Lo 14 °F⇑

Hazardous Weather Outlook
 

Overnight
 
 Cloudy, with a low around -4. South wind around 10 mph.
Friday
 
 A 20 percent chance of snow after 4pm. Increasing clouds, with a high near 26. Wind chill values between -5 and 5. Southwest wind around 10 mph.
Friday Night
 
 A chance of snow and freezing rain before 11pm, then a slight chance of freezing rain between 11pm and midnight. Cloudy, with a low around 20. Southwest wind 5 to 10 mph becoming northwest after midnight. Chance of precipitation is 50%.
Saturday
 
 Mostly sunny, with a high near 23. Northwest wind around 5 mph becoming calm in the afternoon.
Saturday Night
 
 Snow, mainly after midnight. Low around 11. Calm wind becoming north around 5 mph after midnight. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible.
Sunday
 
 A 40 percent chance of snow before noon. Mostly sunny, with a high near 20. North wind 5 to 10 mph.
Sunday Night
 
 Partly cloudy, with a low around -3. North wind around 5 mph becoming calm in the evening.
Monday
 
 Mostly cloudy, with a high near 20. Light and variable wind becoming south 5 to 10 mph in the morning.
Monday Night
 
 Snow likely, mainly after midnight. Mostly cloudy, with a temperature falling to near 14 by 8pm, then rising to around 22 during the remainder of the night. Chance of precipitation is 60%.
Tuesday
 
 A 30 percent chance of snow after noon. Mostly cloudy, with a high near 33.
Tuesday Night
 
 Snow. Low around 24. Chance of precipitation is 80%.
Wednesday
 
 A chance of rain and snow. Mostly cloudy, with a high near 32. Chance of precipitation is 50%.
Wednesday Night
 
 A 20 percent chance of snow. Mostly cloudy, with a low around 7.
Thursday
 
 A 20 percent chance of snow. Partly sunny, with a high near 19.

 

Forecast from NOAA-NWS for Janesville WI.