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.

Light Rain

49°F

9°C

Humidity 79%
Wind Speed Calm
Barometer 29.87 in (1012.2 mb)
Dewpoint 42°F (6°C)
Visibility 10.00 mi
Last update 24 Nov 4:55 pm CST
Extended Forecast for

Ontario WI

  • This Afternoon

    This Afternoon: Rain likely. Cloudy, with a steady temperature around 47. Calm wind. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

    High: 47 °F

    Rain Likely

  • Tonight

    Tonight: Rain, mainly before 5am. Patchy fog before midnight. Low around 41. Calm wind. Chance of precipitation is 90%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 41 °F

    Rain and
    Patchy Fog
    then Chance
    Rain

  • Tuesday

    Tuesday: A chance of rain before noon, then rain likely after 3pm. Cloudy, with a high near 52. Calm wind becoming southwest 5 to 7 mph in the afternoon. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

    High: 52 °F

    Chance Rain
    then Rain
    Likely

  • Tuesday Night

    Tuesday Night: Rain before 1am, then snow likely, possibly mixed with rain between 1am and 2am, then snow likely after 2am. Low around 26. Blustery, with a west wind 9 to 14 mph increasing to 15 to 20 mph after midnight. Winds could gust as high as 40 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.

    Low: 26 °F

    Rain then
    Rain/Snow
    Likely and
    Blustery

  • Wednesday

    Wednesday: A 50 percent chance of snow, mainly before noon. Mostly cloudy, with a high near 33. Windy, with a northwest wind 20 to 28 mph, with gusts as high as 40 mph. New snow accumulation of less than a half inch possible.

    High: 33 °F

    Windy. Chance
    Snow then
    Slight Chance
    Snow

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 19. Blustery, with a northwest wind 11 to 18 mph, with gusts as high as 32 mph.

    Low: 19 °F

    Mostly Cloudy
    and Blustery
    then Mostly
    Cloudy

  • Thanksgiving Day

    Thanksgiving Day: Partly sunny, with a high near 29. Blustery, with a northwest wind 10 to 16 mph, with gusts as high as 25 mph.

    High: 29 °F

    Partly Sunny
    and Blustery

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 14. Northwest wind 5 to 8 mph becoming calm after midnight. Winds could gust as high as 21 mph.

    Low: 14 °F

    Mostly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 29. Light northwest wind.

    High: 29 °F

    Partly Sunny

Detailed Forecast

This Afternoon
Rain likely. Cloudy, with a steady temperature around 47. Calm wind. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Tonight
Rain, mainly before 5am. Patchy fog before midnight. Low around 41. Calm wind. Chance of precipitation is 90%. New precipitation amounts of less than a tenth of an inch possible.
Tuesday
A chance of rain before noon, then rain likely after 3pm. Cloudy, with a high near 52. Calm wind becoming southwest 5 to 7 mph in the afternoon. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Tuesday Night
Rain before 1am, then snow likely, possibly mixed with rain between 1am and 2am, then snow likely after 2am. Low around 26. Blustery, with a west wind 9 to 14 mph increasing to 15 to 20 mph after midnight. Winds could gust as high as 40 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.
Wednesday
A 50 percent chance of snow, mainly before noon. Mostly cloudy, with a high near 33. Windy, with a northwest wind 20 to 28 mph, with gusts as high as 40 mph. New snow accumulation of less than a half inch possible.
Wednesday Night
Mostly cloudy, with a low around 19. Blustery, with a northwest wind 11 to 18 mph, with gusts as high as 32 mph.
Thanksgiving Day
Partly sunny, with a high near 29. Blustery, with a northwest wind 10 to 16 mph, with gusts as high as 25 mph.
Thursday Night
Mostly cloudy, with a low around 14. Northwest wind 5 to 8 mph becoming calm after midnight. Winds could gust as high as 21 mph.
Friday
Partly sunny, with a high near 29. Light northwest wind.
Friday Night
A 50 percent chance of snow. Mostly cloudy, with a low around 17. Calm wind.
Saturday
A 40 percent chance of snow. Mostly cloudy, with a high near 30. Calm wind becoming east around 6 mph in the afternoon.
Saturday Night
A 40 percent chance of snow. Mostly cloudy, with a low around 17. Light and variable wind.
Sunday
A 40 percent chance of snow. Mostly cloudy, with a high near 30. Calm wind becoming northwest 5 to 7 mph in the morning.
Sunday Night
A 40 percent chance of snow. Mostly cloudy, with a low around 14. Northwest wind 3 to 5 mph.
Monday
A 30 percent chance of snow. Partly sunny, with a high near 29. Northwest wind 3 to 7 mph.
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ABOUT THIS FORECAST

 
Point Forecast:
Ontario WI
 43.73°N 90.58°W
Last Update:
5:31 pm CST Nov 24, 2025
Forecast Valid:
5pm CST Nov 24, 2025-6pm CST Dec 1, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation