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.

Mostly Cloudy

84°F

29°C

Humidity 70%
Wind Speed S 8 mph
Barometer 29.90 in
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index90°F (32°C)
Last update 31 Aug 5:45 pm CDT
Extended Forecast for

Janesville WI

  • This Afternoon

    This Afternoon: A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87. Southwest wind around 10 mph.

    High: 87 °F

    Chance
    Showers

  • Tonight

    Tonight: A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers between 7pm and 9pm. Patchy fog after 4am. Otherwise, partly cloudy, with a low around 71. Southwest wind around 5 mph becoming calm in the evening. Chance of precipitation is 20%.

    Low: 71 °F

    Slight Chance
    T-storms then
    Patchy Fog

  • Tuesday

    Tuesday: Patchy fog before 9am. Otherwise, partly sunny, with a high near 89. Heat index values as high as 97. Calm wind becoming west around 5 mph in the morning.

    High: 89 °F

    Patchy Fog
    then Partly
    Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 72. Southwest wind around 5 mph becoming calm in the evening.

    Low: 72 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny and hot, with a high near 90. Light southwest wind increasing to 5 to 10 mph in the morning.

    High: 90 °F

    Hot

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 71. Southwest wind around 5 mph becoming calm in the evening.

    Low: 71 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm before 1pm. Partly sunny, with a high near 86. Calm wind becoming west around 5 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 86 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: A 50 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 69. Southeast wind around 5 mph.

    Low: 69 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 86.

    High: 86 °F

    Chance
    T-storms

Detailed Forecast

This Afternoon
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87. Southwest wind around 10 mph.
Tonight
A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers between 7pm and 9pm. Patchy fog after 4am. Otherwise, partly cloudy, with a low around 71. Southwest wind around 5 mph becoming calm in the evening. Chance of precipitation is 20%.
Tuesday
Patchy fog before 9am. Otherwise, partly sunny, with a high near 89. Heat index values as high as 97. Calm wind becoming west around 5 mph in the morning.
Tuesday Night
Partly cloudy, with a low around 72. Southwest wind around 5 mph becoming calm in the evening.
Wednesday
Mostly sunny and hot, with a high near 90. Light southwest wind increasing to 5 to 10 mph in the morning.
Wednesday Night
A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 71. Southwest wind around 5 mph becoming calm in the evening.
Thursday
Showers likely and possibly a thunderstorm before 1pm. Partly sunny, with a high near 86. Calm wind becoming west around 5 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Thursday Night
A 50 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 69. Southeast wind around 5 mph.
Friday
A 30 percent chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 86.
Friday Night
A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 67.
Saturday
A 20 percent chance of showers. Partly sunny, with a high near 83.
Saturday Night
A 20 percent chance of showers. Partly cloudy, with a low around 64.
Sunday
A 20 percent chance of showers. Mostly sunny, with a high near 81.
Sunday Night
A 20 percent chance of showers. Partly cloudy, with a low around 62.
Labor Day
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 81.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Janesville WI
 42.69°N 89.03°W (Elev. 860 ft)
Last Update:
5:52 pm CDT Aug 31, 2026
Forecast Valid:
5pm CDT Aug 31, 2026-6pm CDT Sep 7, 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