Wisconsin · NWS MKX office

Janesville, WI weather

It is 48°F and clear at Janesville-Rock County as of Oct 28, 3:55 AM CDT. Overnight: Mostly Clear, low near 51°F, 1% chance of precipitation. Forecast from the National Weather Service, issued Oct 28, 3:32 AM CDT.

Updated Oct 28, 4:19 AM CDT (snapshot)

Current conditions

Temperature

48°F

Clear

Wind

Calm

Humidity 87% · dew point 45°F

Pressure · visibility

30.17 inHg

Visibility 10 mi

Observed at Janesville-Rock County (KJVL), Oct 28, 3:55 AM CDT. Station readings can lag or be missing.

Alerts for this area

No active NWS alerts cover the Janesville forecast zone right now.

Around the NWS MKX forecast area

No active alerts in zones served by the MKX office near Janesville.

From the alert snapshot of Oct 28, 2026, 5:12 AM EDT. No alerts are active anywhere in Wisconsin.

For official warnings, check weather.gov and your local authorities. OpenForecast repeats National Weather Service alerts and may be delayed or incomplete. Follow instructions from emergency officials.

Next 24 hours

Hourly forecast for Janesville (local time)
TimeTempForecastPrecip. chanceWind
Wed 6 AM52°FSunny1%S 5 mph
Wed 7 AM51°FSunny0%S 5 mph
Wed 8 AM51°FSunny0%S 5 mph
Wed 9 AM55°FSunny0%S 5 mph
Wed 10 AM60°FSunny0%S 5 mph
Wed 11 AM64°FSunny0%S 5 mph
Wed 12 PM67°FSunny0%S 10 mph
Wed 1 PM70°FSunny0%S 10 mph
Wed 2 PM72°FSunny1%S 10 mph
Wed 3 PM73°FSunny1%S 10 mph
Wed 4 PM73°FSunny1%S 10 mph
Wed 5 PM71°FSunny1%S 10 mph
Wed 6 PM68°FPartly Cloudy3%S 10 mph
Wed 7 PM65°FPartly Cloudy5%S 10 mph
Wed 8 PM64°FPartly Cloudy6%S 10 mph
Wed 9 PM63°FPartly Cloudy6%S 15 mph
Wed 10 PM63°FMostly Cloudy7%S 15 mph
Wed 11 PM63°FMostly Cloudy8%S 15 mph
Thu 12 AM62°FMostly Cloudy14%S 15 mph
Thu 1 AM61°FSlight Chance Showers And Thunderstorms19%S 15 mph
Thu 2 AM61°FChance Showers And Thunderstorms37%S 10 mph
Thu 3 AM60°FShowers And Thunderstorms Likely55%SW 10 mph
Thu 4 AM59°FChance Showers And Thunderstorms33%SW 10 mph
Thu 5 AM59°FMostly Cloudy13%SW 10 mph

Hourly values come from the NWS gridded forecast for the 2.5 km grid square that covers the city's center point. Conditions elsewhere in Janesville can differ.

7-day forecast

Overnight

Low 51°F

Mostly clear, with a low around 51. South wind 0 to 5 mph.

Wednesday

High 74°F·Low 57°F

Sunny, with a high near 74. South wind 5 to 10 mph.

Wednesday Night: A slight chance of showers and thunderstorms between 1am and 2am, then showers and thunderstorms likely between 2am and 5am. Mostly cloudy, with a low around 57. South wind 10 to 15 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.

Thursday

High 68°F·Low 39°F

Mostly sunny, with a high near 68. West wind 5 to 10 mph. New rainfall amounts less than a tenth of an inch possible.

Thursday Night: Mostly clear, with a low around 39. North wind 0 to 5 mph.

Friday

High 61°F·Low 45°F

A slight chance of rain showers after 1pm. Partly sunny, with a high near 61. East wind 0 to 5 mph. Chance of precipitation is 20%.

Friday Night: A slight chance of rain showers. Mostly cloudy, with a low around 45. East wind 0 to 5 mph. Chance of precipitation is 20%.

Saturday

High 63°F·Low 47°F

A chance of rain showers. Mostly cloudy, with a high near 63. East wind around 5 mph. Chance of precipitation is 40%.

Saturday Night: A chance of rain showers. Mostly cloudy, with a low around 47. Chance of precipitation is 30%.

Sunday

High 66°F·Low 49°F

A chance of rain showers. Mostly cloudy. High near 66, with temperatures falling to around 61 in the afternoon. Chance of precipitation is 30%.

Sunday Night: A slight chance of rain showers. Mostly cloudy, with a low around 49. Chance of precipitation is 20%.

Monday

High 66°F·Low 51°F

A chance of rain showers. Mostly cloudy, with a high near 66. Chance of precipitation is 30%.

Monday Night: A chance of rain showers. Mostly cloudy, with a low around 51. Chance of precipitation is 50%.

Tuesday

High 64°F

Rain showers likely. Mostly cloudy, with a high near 64. Chance of precipitation is 60%.

Nearby cities

Larger cities in the area

Other cities in Rock County

See every city we cover in Wisconsin, or check all active alerts.

About this forecast

Forecast office
Janesville is served by the National Weather Service MKX forecast office, forecast zone WIZ069, county zone WIC105.
Location used
The Census Bureau's internal point for Janesville (42.6847, -89.0132), in Rock County. Population: 66,428 (2024 estimate), number 10 of the 42 Wisconsin cities on this site.
Radar
Nearest NWS radar: KMKX. View it on radar.weather.gov.

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Sources

  • Forecast, hourly forecast, observations and alerts: National Weather Service API, api.weather.gov/points/42.6847,-89.0132 (forecast issued Oct 28, 3:32 AM CDT).
  • Official forecast page: forecast.weather.gov.
  • City location and population: U.S. Census Bureau, Vintage 2024 population estimates and 2024 Gazetteer files.
  • Snapshot taken Oct 28, 2026. The NWS and Census Bureau do not endorse OpenForecast.

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