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.

Mostly Cloudy

54°F

12°C

Humidity 28%
Wind Speed Calm
Barometer 30.17 in (1022.4 mb)
Dewpoint 22°F (-6°C)
Visibility 10.00 mi
Last update 24 Mar 3:55 pm CDT
Extended Forecast for

Ontario WI

  • Tonight

    Tonight: Mostly cloudy, with a low around 34. Calm wind.

    Low: 34 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 66. Light and variable wind becoming southwest 5 to 8 mph in the morning.

    High: 66 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 44. Calm wind.

    Low: 44 °F

    Partly Cloudy

  • Thursday

    Thursday: A 30 percent chance of showers, mainly before 1pm. Partly sunny, with a high near 65. Light and variable wind becoming north 6 to 11 mph in the morning. Winds could gust as high as 20 mph.

    High: 65 °F

    Chance
    Showers

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 24. North wind 6 to 10 mph, with gusts as high as 21 mph.

    Low: 24 °F

    Mostly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 44. Light north wind becoming northwest 5 to 9 mph in the morning.

    High: 44 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 23. Northwest wind around 6 mph becoming calm in the evening.

    Low: 23 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 54. Light southwest wind becoming west 5 to 10 mph in the morning. Winds could gust as high as 18 mph.

    High: 54 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 32. Light and variable wind.

    Low: 32 °F

    Partly Cloudy

Detailed Forecast

Tonight
Mostly cloudy, with a low around 34. Calm wind.
Wednesday
Mostly sunny, with a high near 66. Light and variable wind becoming southwest 5 to 8 mph in the morning.
Wednesday Night
Partly cloudy, with a low around 44. Calm wind.
Thursday
A 30 percent chance of showers, mainly before 1pm. Partly sunny, with a high near 65. Light and variable wind becoming north 6 to 11 mph in the morning. Winds could gust as high as 20 mph.
Thursday Night
Mostly cloudy, with a low around 24. North wind 6 to 10 mph, with gusts as high as 21 mph.
Friday
Mostly sunny, with a high near 44. Light north wind becoming northwest 5 to 9 mph in the morning.
Friday Night
Mostly clear, with a low around 23. Northwest wind around 6 mph becoming calm in the evening.
Saturday
Mostly sunny, with a high near 54. Light southwest wind becoming west 5 to 10 mph in the morning. Winds could gust as high as 18 mph.
Saturday Night
Partly cloudy, with a low around 32. Light and variable wind.
Sunday
Mostly sunny, with a high near 61. South wind 5 to 10 mph, with gusts as high as 18 mph.
Sunday Night
Partly cloudy, with a low around 40. South wind around 7 mph.
Monday
A 20 percent chance of showers. Mostly sunny, with a high near 66. Southeast wind 5 to 8 mph.
Monday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 41. Southeast wind 6 to 8 mph, with gusts as high as 18 mph.
Tuesday
A 30 percent chance of showers. Partly sunny, with a high near 63. East wind 8 to 13 mph, with gusts as high as 22 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:
1:26 pm CDT Mar 24, 2026
Forecast Valid:
3pm CDT Mar 24, 2026-6pm CDT Mar 31, 2026
 
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Additional Resources

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Chance of Precipitation