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.

Fair

28°F

-2°C

Humidity 94%
Wind Speed Calm
Barometer 30.14 in (1022.0 mb)
Dewpoint 26°F (-3°C)
Visibility 8.00 mi
Last update 2 Nov 7:55 am CST
Extended Forecast for

Ontario WI

  • Today

    Today: Patchy fog before 9am. Otherwise, mostly cloudy, then gradually becoming sunny, with a high near 51. Breezy, with a south wind 5 to 10 mph increasing to 12 to 17 mph in the afternoon. Winds could gust as high as 30 mph.

    High: 51 °F

    Patchy Fog
    then Mostly
    Sunny and
    Breezy

  • Tonight

    Tonight: A slight chance of showers between midnight and 2am. Cloudy, then gradual clearing toward daybreak, with a low around 36. South wind 6 to 13 mph becoming west after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 20%.

    Low: 36 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Monday

    Monday: Sunny, with a high near 58. West wind 6 to 13 mph, with gusts as high as 21 mph.

    High: 58 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 32. West wind around 5 mph becoming calm in the evening.

    Low: 32 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 60. Calm wind becoming south 5 to 7 mph in the morning.

    High: 60 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 37. Light and variable wind.

    Low: 37 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 56. Light northwest wind increasing to 5 to 9 mph in the morning.

    High: 56 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 31. Light and variable wind.

    Low: 31 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 56. Light southeast wind becoming south 8 to 13 mph in the morning. Winds could gust as high as 21 mph.

    High: 56 °F

    Mostly Cloudy

Detailed Forecast

Today
Patchy fog before 9am. Otherwise, mostly cloudy, then gradually becoming sunny, with a high near 51. Breezy, with a south wind 5 to 10 mph increasing to 12 to 17 mph in the afternoon. Winds could gust as high as 30 mph.
Tonight
A slight chance of showers between midnight and 2am. Cloudy, then gradual clearing toward daybreak, with a low around 36. South wind 6 to 13 mph becoming west after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 20%.
Monday
Sunny, with a high near 58. West wind 6 to 13 mph, with gusts as high as 21 mph.
Monday Night
Partly cloudy, with a low around 32. West wind around 5 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 60. Calm wind becoming south 5 to 7 mph in the morning.
Tuesday Night
Mostly cloudy, with a low around 37. Light and variable wind.
Wednesday
Mostly sunny, with a high near 56. Light northwest wind increasing to 5 to 9 mph in the morning.
Wednesday Night
Partly cloudy, with a low around 31. Light and variable wind.
Thursday
Mostly cloudy, with a high near 56. Light southeast wind becoming south 8 to 13 mph in the morning. Winds could gust as high as 21 mph.
Thursday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 40. South wind around 7 mph becoming west after midnight. Winds could gust as high as 21 mph.
Friday
Mostly sunny, with a high near 56. West wind 6 to 13 mph.
Friday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 32. Northwest wind around 6 mph becoming light and variable in the evening.
Saturday
A 30 percent chance of showers. Partly sunny, with a high near 52. Light and variable wind becoming southwest 6 to 11 mph in the morning.
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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:
7:41 am CST Nov 2, 2025
Forecast Valid:
8am CST Nov 2, 2025-6pm CST Nov 8, 2025
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation