National Weather Service Forecast for: Sun Prairie WI
Issued by: National Weather Service Milwaukee, WI
Updated: 8:36 pm CDT Jun 18, 2026
 
Tonight

Tonight: Mostly clear, with a low around 53. West wind around 5 mph.
Mostly Clear

 Juneteenth

Juneteenth: Sunny, with a high near 75. Northwest wind 5 to 10 mph.
Sunny

 Friday
Night
Friday Night: A 40 percent chance of showers and thunderstorms, mainly before 11pm. Partly cloudy, with a low around 54. Southwest wind around 5 mph.
Chance
T-storms then
Partly Cloudy
 Saturday

Saturday: Mostly cloudy, then gradually becoming sunny, with a high near 76. Northwest wind 5 to 10 mph.
Decreasing
Clouds

 Saturday
Night
Saturday Night: Partly cloudy, with a low around 53. Northwest wind around 5 mph becoming calm in the evening.
Partly Cloudy

 Sunday

Sunday: A 50 percent chance of showers, mainly after 1pm. Mostly cloudy, with a high near 72. Light east wind becoming southeast 5 to 10 mph in the morning.
Slight Chance
Showers then
Chance
Showers
 Sunday
Night
Sunday Night: A 40 percent chance of showers, mainly before 1am. Mostly cloudy, with a low around 52. Northeast wind around 10 mph.
Chance
Showers

 Monday

Monday: Mostly sunny, with a high near 74. Northeast wind around 10 mph.
Mostly Sunny

 Monday
Night
Monday Night: Partly cloudy, with a low around 52.
Partly Cloudy
Lo 53 °F Hi 75 °F Lo 54 °F Hi 76 °F Lo 53 °F Hi 72 °F Lo 52 °F Hi 74 °F Lo 52 °F

Hazardous Weather Outlook
 

Tonight
 
 Mostly clear, with a low around 53. West wind around 5 mph.
Juneteenth
 
 Sunny, with a high near 75. Northwest wind 5 to 10 mph.
Friday Night
 
 A 40 percent chance of showers and thunderstorms, mainly before 11pm. Partly cloudy, with a low around 54. Southwest wind around 5 mph.
Saturday
 
 Mostly cloudy, then gradually becoming sunny, with a high near 76. Northwest wind 5 to 10 mph.
Saturday Night
 
 Partly cloudy, with a low around 53. Northwest wind around 5 mph becoming calm in the evening.
Sunday
 
 A 50 percent chance of showers, mainly after 1pm. Mostly cloudy, with a high near 72. Light east wind becoming southeast 5 to 10 mph in the morning.
Sunday Night
 
 A 40 percent chance of showers, mainly before 1am. Mostly cloudy, with a low around 52. Northeast wind around 10 mph.
Monday
 
 Mostly sunny, with a high near 74. Northeast wind around 10 mph.
Monday Night
 
 Partly cloudy, with a low around 52.
Tuesday
 
 A 20 percent chance of showers after 1pm. Mostly sunny, with a high near 75.
Tuesday Night
 
 A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 55.
Wednesday
 
 A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 75.
Wednesday Night
 
 A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 54.
Thursday
 
 A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 76.

 

Forecast from NOAA-NWS for Sun Prairie WI.