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

Hazardous Weather Conditions

Current conditions at

Janesville-Rock County (KJVL)

Lat: 42.62°NLon: 89.04°WElev: 801ft.

Fair

66°F

19°C

Humidity 83%
Wind Speed Calm
Barometer 29.89 in
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 17 May 3:55 am CDT
Extended Forecast for

Janesville WI

  • Overnight

    Overnight: A 40 percent chance of showers and thunderstorms. Cloudy, with a low around 60. Southeast wind around 5 mph.

    Low: 60 °F

    Chance
    T-storms

  • Sunday

    Sunday: Showers and thunderstorms likely, mainly before 2pm. Mostly cloudy, with a high near 82. East wind 10 to 15 mph becoming south in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 82 °F

    Showers
    Likely then
    Chance
    T-storms

  • Sunday Night

    Sunday Night: A 30 percent chance of showers and thunderstorms, mainly after 4am. Partly cloudy, with a low around 67. South wind around 15 mph, with gusts as high as 30 mph.

    Low: 67 °F

    Partly Cloudy
    then Chance
    T-storms

  • Monday

    Monday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 10am. Partly sunny, with a high near 80. Breezy, with a southwest wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 80 °F

    Showers
    Likely and
    Breezy

  • Monday Night

    Monday Night: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 1am. Low around 64. Breezy, with a south wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 64 °F

    Chance
    T-storms then
    Showers and
    Breezy

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 76. Breezy, with a south wind 15 to 20 mph becoming west in the afternoon. Winds could gust as high as 35 mph.

    High: 76 °F

    Chance
    T-storms and
    Breezy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 46. Northwest wind 10 to 15 mph.

    Low: 46 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 63. North wind around 10 mph.

    High: 63 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 41.

    Low: 41 °F

    Partly Cloudy

Detailed Forecast

Overnight
A 40 percent chance of showers and thunderstorms. Cloudy, with a low around 60. Southeast wind around 5 mph.
Sunday
Showers and thunderstorms likely, mainly before 2pm. Mostly cloudy, with a high near 82. East wind 10 to 15 mph becoming south in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Sunday Night
A 30 percent chance of showers and thunderstorms, mainly after 4am. Partly cloudy, with a low around 67. 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 10am. Partly sunny, with a high near 80. Breezy, with a southwest wind 15 to 20 mph, with gusts as high as 30 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 and possibly a thunderstorm after 1am. Low around 64. Breezy, with a south wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday
A 50 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 76. Breezy, with a south wind 15 to 20 mph becoming west in the afternoon. Winds could gust as high as 35 mph.
Tuesday Night
Mostly cloudy, with a low around 46. Northwest wind 10 to 15 mph.
Wednesday
Mostly sunny, with a high near 63. North wind around 10 mph.
Wednesday Night
Partly cloudy, with a low around 41.
Thursday
Mostly sunny, with a high near 64.
Thursday Night
Partly cloudy, with a low around 45.
Friday
Partly sunny, with a high near 69.
Friday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 49.
Saturday
Partly sunny, with a high near 75.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Janesville WI
 42.67°N 89.04°W (Elev. 774 ft)
Last Update:
3:32 am CDT May 17, 2026
Forecast Valid:
4am CDT May 17, 2026-6pm CDT May 23, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

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