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

Hazardous Weather Conditions

Current conditions at

Sparta, Sparta / Fort McCoy Airport (KCMY)

Lat: 43.96°NLon: 90.74°WElev: 837ft.

A Few Clouds

79°F

26°C

Humidity 83%
Wind Speed Calm
Barometer 29.82 in (1009.7 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 16 Jun 4:55 pm CDT
Extended Forecast for

Ontario WI

  • Tonight

    Tonight: Showers and thunderstorms likely, mainly before 1am. Mostly cloudy, with a low around 65. South wind 3 to 5 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 65 °F

    T-storms
    Likely

  • Tuesday

    Tuesday: A 10 percent chance of showers and thunderstorms after 5pm. Partly sunny, with a high near 82. West wind around 6 mph.

    High: 82 °F

    Partly Sunny
    then Slight
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 62. Calm wind. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 62 °F

    Chance
    T-storms then
    Showers
    Likely

  • Wednesday

    Wednesday: Showers likely and possibly a thunderstorm before 7am, then showers likely between 7am and 10am, then showers likely and possibly a thunderstorm after 10am. Mostly cloudy, with a high near 77. Calm wind becoming northeast 5 to 7 mph in the afternoon. Chance of precipitation is 70%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 77 °F

    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 58. North wind around 6 mph becoming calm in the evening.

    Low: 58 °F

    Chance
    T-storms then
    Chance
    Showers

  • Juneteenth

    Juneteenth: A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 83. Calm wind becoming west 5 to 8 mph in the morning.

    High: 83 °F

    Sunny then
    Slight Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms. Mostly clear, with a low around 60. West wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%.

    Low: 60 °F

    Chance
    T-storms

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 83. Light south wind increasing to 5 to 10 mph in the morning. Winds could gust as high as 18 mph.

    High: 83 °F

    Chance
    Showers then
    Chance
    T-storms

  • Friday Night

    Friday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 68. South wind around 9 mph, with gusts as high as 21 mph.

    Low: 68 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Showers and thunderstorms likely, mainly before 1am. Mostly cloudy, with a low around 65. South wind 3 to 5 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday
A 10 percent chance of showers and thunderstorms after 5pm. Partly sunny, with a high near 82. West wind around 6 mph.
Tuesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 62. Calm wind. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday
Showers likely and possibly a thunderstorm before 7am, then showers likely between 7am and 10am, then showers likely and possibly a thunderstorm after 10am. Mostly cloudy, with a high near 77. Calm wind becoming northeast 5 to 7 mph in the afternoon. Chance of precipitation is 70%. New rainfall amounts between a half and three quarters of an inch possible.
Wednesday Night
A 30 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 58. North wind around 6 mph becoming calm in the evening.
Juneteenth
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 83. Calm wind becoming west 5 to 8 mph in the morning.
Thursday Night
A chance of showers and thunderstorms. Mostly clear, with a low around 60. West wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%.
Friday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 83. Light south wind increasing to 5 to 10 mph in the morning. Winds could gust as high as 18 mph.
Friday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 68. South wind around 9 mph, with gusts as high as 21 mph.
Saturday
Mostly sunny, with a high near 91. Southwest wind 9 to 11 mph, with gusts as high as 21 mph.
Saturday Night
Mostly clear, with a low around 73. South wind 6 to 8 mph, with gusts as high as 20 mph.
Sunday
Sunny, with a high near 90. South wind 9 to 15 mph, with gusts as high as 25 mph.
Sunday Night
A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 73. South wind 9 to 11 mph, with gusts as high as 24 mph.
Monday
A 50 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87. Southwest wind 9 to 11 mph, with gusts as high as 21 mph.
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ABOUT THIS FORECAST

 
Point Forecast:
Ontario WI
 43.73°N 90.58°W
Last Update:
5:29 pm CDT Jun 16, 2025
Forecast Valid:
6pm CDT Jun 16, 2025-6pm CDT Jun 23, 2025
 
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Additional Resources

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Chance of Precipitation