National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Janesville-Rock County (KJVL)

Lat: 42.62°NLon: 89.04°WElev: 801ft.

Fair

55°F

13°C

Humidity 47%
Wind Speed SE 7 mph
Barometer 29.96 in
Dewpoint 36°F (2°C)
Visibility 10.00 mi
Wind Chill53°F (12°C)
Last update 14 May 11:15 pm CDT
Extended Forecast for

Janesville WI

  • Tonight

    Tonight: A chance of showers and thunderstorms. Mostly cloudy, with a low around 50. South wind around 10 mph. Chance of precipitation is 50%.

    Low: 50 °F

    Chance
    T-storms

  • Friday

    Friday: Mostly cloudy, then gradually becoming sunny, with a high near 77. South wind around 15 mph, with gusts as high as 30 mph.

    High: 77 °F

    Decreasing
    Clouds

  • Friday Night

    Friday Night: A chance of showers and thunderstorms before 2am, then showers likely and possibly a thunderstorm between 2am and 4am, then a chance of showers and thunderstorms after 4am. Increasing clouds, with a low around 57. South wind 5 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 57 °F

    Mostly Clear
    then Showers
    Likely

  • Saturday

    Saturday: A chance of showers and thunderstorms before 2pm, then a slight chance of showers and thunderstorms after 5pm. Cloudy through mid morning, then gradual clearing, with a high near 83. West wind around 5 mph. Chance of precipitation is 30%.

    High: 83 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms before 1am, then showers likely and possibly a thunderstorm between 1am and 4am, then showers likely after 4am. Increasing clouds, with a low around 57. Southeast wind around 5 mph becoming calm. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 57 °F

    Chance
    T-storms then
    Showers
    Likely

  • Sunday

    Sunday: A chance of showers before 1pm, then a slight chance of showers and thunderstorms between 1pm and 4pm, then a slight chance of showers after 4pm. Partly sunny, with a high near 85. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 50%.

    High: 85 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 65. South wind around 15 mph, with gusts as high as 30 mph.

    Low: 65 °F

    Partly Cloudy

  • Monday

    Monday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Increasing clouds, with a high near 86. Breezy, with a south wind around 20 mph, with gusts as high as 35 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 86 °F

    Breezy.
    Chance
    Showers then
    Showers
    Likely

  • Monday Night

    Monday Night: A chance of showers and thunderstorms, then showers likely after 1am. Mostly cloudy, with a low around 65. Breezy. Chance of precipitation is 70%.

    Low: 65 °F

    Breezy.
    Chance
    T-storms then
    Showers
    Likely

Detailed Forecast

Tonight
A chance of showers and thunderstorms. Mostly cloudy, with a low around 50. South wind around 10 mph. Chance of precipitation is 50%.
Friday
Mostly cloudy, then gradually becoming sunny, with a high near 77. South wind around 15 mph, with gusts as high as 30 mph.
Friday Night
A chance of showers and thunderstorms before 2am, then showers likely and possibly a thunderstorm between 2am and 4am, then a chance of showers and thunderstorms after 4am. Increasing clouds, with a low around 57. South wind 5 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday
A chance of showers and thunderstorms before 2pm, then a slight chance of showers and thunderstorms after 5pm. Cloudy through mid morning, then gradual clearing, with a high near 83. West wind around 5 mph. Chance of precipitation is 30%.
Saturday Night
A chance of showers and thunderstorms before 1am, then showers likely and possibly a thunderstorm between 1am and 4am, then showers likely after 4am. Increasing clouds, with a low around 57. Southeast wind around 5 mph becoming calm. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Sunday
A chance of showers before 1pm, then a slight chance of showers and thunderstorms between 1pm and 4pm, then a slight chance of showers after 4pm. Partly sunny, with a high near 85. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 50%.
Sunday Night
Partly cloudy, with a low around 65. South wind around 15 mph, with gusts as high as 30 mph.
Monday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Increasing clouds, with a high near 86. Breezy, with a south wind around 20 mph, with gusts as high as 35 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday Night
A chance of showers and thunderstorms, then showers likely after 1am. Mostly cloudy, with a low around 65. Breezy. Chance of precipitation is 70%.
Tuesday
A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 82. Breezy. Chance of precipitation is 50%.
Tuesday Night
A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 51.
Wednesday
A 20 percent chance of showers. Mostly sunny, with a high near 70.
Wednesday Night
Partly cloudy, with a low around 46.
Thursday
Partly sunny, with a high near 69.
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ABOUT THIS FORECAST

 
Point Forecast:
Janesville WI
 42.67°N 89.04°W (Elev. 774 ft)
Last Update:
11:31 pm CDT May 14, 2026
Forecast Valid:
11pm CDT May 14, 2026-6pm CDT May 21, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation