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

48°F

9°C

Humidity 64%
Wind Speed S 7 G 17 mph
Barometer 30.24 in (1024.8 mb)
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Wind Chill45°F (7°C)
Last update 18 Oct 8:55 am CDT
Extended Forecast for

Ontario WI

  • Today

    Today: Sunny, with a high near 63. Breezy, with a southwest wind 10 to 17 mph, with gusts as high as 28 mph.

    High: 63 °F

    Sunny and
    Breezy

  • Tonight

    Tonight: Clear, with a low around 39. South wind 5 to 10 mph becoming light after midnight. Winds could gust as high as 23 mph.

    Low: 39 °F

    Clear

  • Monday

    Monday: Mostly sunny, with a high near 65. Light south wind.

    High: 65 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 38. Calm wind.

    Low: 38 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 66. Calm wind becoming south around 5 mph in the afternoon.

    High: 66 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 42. Calm wind.

    Low: 42 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 68. Calm wind becoming south around 5 mph in the afternoon.

    High: 68 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 48. Calm wind.

    Low: 48 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 73. Calm wind.

    High: 73 °F

    Mostly Sunny

Detailed Forecast

Today
Sunny, with a high near 63. Breezy, with a southwest wind 10 to 17 mph, with gusts as high as 28 mph.
Tonight
Clear, with a low around 39. South wind 5 to 10 mph becoming light after midnight. Winds could gust as high as 23 mph.
Monday
Mostly sunny, with a high near 65. Light south wind.
Monday Night
Mostly clear, with a low around 38. Calm wind.
Tuesday
Sunny, with a high near 66. Calm wind becoming south around 5 mph in the afternoon.
Tuesday Night
Mostly clear, with a low around 42. Calm wind.
Wednesday
Sunny, with a high near 68. Calm wind becoming south around 5 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 48. Calm wind.
Thursday
Mostly sunny, with a high near 73. Calm wind.
Thursday Night
Mostly clear, with a low around 47. Calm wind.
Friday
Mostly sunny, with a high near 72. Calm wind becoming south 5 to 9 mph in the morning.
Friday Night
Partly cloudy, with a low around 50. South wind around 6 mph, with gusts as high as 18 mph.
Saturday
Partly sunny, with a high near 71. South wind 6 to 13 mph, with gusts as high as 21 mph.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Ontario WI
 43.73°N 90.55°W
Last Update:
8:52 am CDT Oct 18, 2026
Forecast Valid:
9am CDT Oct 18, 2026-6pm CDT Oct 24, 2026
 
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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