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

Sparta, Sparta / Fort McCoy Airport (KCMY)

Lat: 43.96°NLon: 90.74°WElev: 837ft.

A Few Clouds

27°F

-3°C

Humidity 74%
Wind Speed W 6 mph
Barometer 30.29 in (1027.3 mb)
Dewpoint 19°F (-7°C)
Visibility 10.00 mi
Wind Chill20°F (-7°C)
Last update 11 Jan 2:55 pm CST
Extended Forecast for

Ontario WI

  • Tonight

    Tonight: Partly cloudy, with a steady temperature around 26. Southwest wind 5 to 8 mph, with gusts as high as 20 mph.

    Low: 26 °F

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 44. West wind 3 to 7 mph.

    High: 44 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Increasing clouds, with a low around 30. Calm wind becoming southwest around 6 mph after midnight.

    Low: 30 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: A 30 percent chance of rain, mainly before noon. Partly sunny, with a high near 46. Breezy, with a west wind 9 to 17 mph, with gusts as high as 29 mph.

    High: 46 °F

    Chance Rain
    and Breezy

  • Tuesday Night

    Tuesday Night: A chance of rain and snow between midnight and 3am, then a chance of snow after 3am. Mostly cloudy, with a low around 22. Blustery, with a west wind 13 to 16 mph, with gusts as high as 33 mph. Chance of precipitation is 30%.

    Low: 22 °F

    Mostly Cloudy
    then Chance
    Rain/Snow and
    Blustery

  • Wednesday

    Wednesday: A 30 percent chance of snow before noon. Partly sunny, with a high near 28. Blustery, with a north wind 17 to 21 mph, with gusts as high as 34 mph.

    High: 28 °F

    Blustery.
    Chance Snow
    then Partly
    Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 9. North wind 6 to 11 mph becoming light after midnight. Winds could gust as high as 24 mph.

    Low: 9 °F

    Partly Cloudy

  • Thursday

    Thursday: A 30 percent chance of snow after noon. Mostly sunny, with a high near 27. Calm wind becoming south around 6 mph in the afternoon.

    High: 27 °F

    Mostly Sunny
    then Chance
    Snow

  • Thursday Night

    Thursday Night: A 50 percent chance of snow. Mostly cloudy, with a low around 20. South wind around 6 mph.

    Low: 20 °F

    Chance Snow

Detailed Forecast

Tonight
Partly cloudy, with a steady temperature around 26. Southwest wind 5 to 8 mph, with gusts as high as 20 mph.
Monday
Mostly sunny, with a high near 44. West wind 3 to 7 mph.
Monday Night
Increasing clouds, with a low around 30. Calm wind becoming southwest around 6 mph after midnight.
Tuesday
A 30 percent chance of rain, mainly before noon. Partly sunny, with a high near 46. Breezy, with a west wind 9 to 17 mph, with gusts as high as 29 mph.
Tuesday Night
A chance of rain and snow between midnight and 3am, then a chance of snow after 3am. Mostly cloudy, with a low around 22. Blustery, with a west wind 13 to 16 mph, with gusts as high as 33 mph. Chance of precipitation is 30%.
Wednesday
A 30 percent chance of snow before noon. Partly sunny, with a high near 28. Blustery, with a north wind 17 to 21 mph, with gusts as high as 34 mph.
Wednesday Night
Partly cloudy, with a low around 9. North wind 6 to 11 mph becoming light after midnight. Winds could gust as high as 24 mph.
Thursday
A 30 percent chance of snow after noon. Mostly sunny, with a high near 27. Calm wind becoming south around 6 mph in the afternoon.
Thursday Night
A 50 percent chance of snow. Mostly cloudy, with a low around 20. South wind around 6 mph.
Friday
Snow likely, mainly after noon. Mostly cloudy, with a high near 30. South wind 5 to 9 mph becoming west in the afternoon. Chance of precipitation is 70%.
Friday Night
A 30 percent chance of snow. Mostly cloudy, with a low around 10. Northwest wind around 7 mph.
Saturday
A 20 percent chance of snow. Partly sunny, with a high near 19. Northwest wind 6 to 10 mph, with gusts as high as 18 mph.
Saturday Night
Mostly cloudy, with a low around 5. West wind around 8 mph, with gusts as high as 18 mph.
Sunday
Partly sunny, with a high near 22. West wind 7 to 10 mph, with gusts as high as 18 mph.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Ontario WI
 43.73°N 90.58°W
Last Update:
3:26 pm CST Jan 11, 2026
Forecast Valid:
3pm CST Jan 11, 2026-6pm CST Jan 18, 2026
 
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Additional Resources

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High Temperature

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Chance of Precipitation