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

Heavy Rainfall and Flooding in the Mid-Atlantic; Heat and Wildfire Concerns in the West

Slow moving showers and thunderstorms may result in flash flooding for portions of the mid-Atlantic region through tonight. Meanwhile, excessive heat will continue to build across the West through Tuesday. Heat Advisories and Extreme Heat Warnings are in effect. Fire Weather concerns continue for the West with dry and breezy conditions. Watching the tropics across the Southeast. Read More >

Hazardous Weather Conditions

Current conditions at

Mount Vernon Airport (KMVN)

Lat: 38.33°NLon: 88.85°WElev: 466ft.

Mostly Cloudy

81°F

27°C

Humidity 82%
Wind Speed S 5 mph
Barometer 30.03 in
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 14 Jul 7:56 pm CDT
Extended Forecast for

Nason IL

  • Tonight

    Tonight: A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers and thunderstorms after 4am. Patchy fog after 1am. Otherwise, mostly cloudy, with a low around 72. South southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 20%.

    Low: 72 °F

    Slight Chance
    T-storms and
    Patchy Fog

  • Tuesday

    Tuesday: Showers and thunderstorms likely, mainly after 4pm. Patchy fog before 8am. Otherwise, partly sunny, with a high near 89. Calm wind becoming south 5 to 8 mph in the morning. Chance of precipitation is 60%.

    High: 89 °F

    Chance
    T-storms and
    Patchy Fog
    then T-storms
    Likely

  • Tuesday Night

    Tuesday Night: Showers and thunderstorms likely before 4am, then a slight chance of showers. Mostly cloudy, with a low around 74. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.

    Low: 74 °F

    T-storms
    Likely then
    Slight Chance
    T-storms

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. Southwest wind 3 to 7 mph.

    High: 92 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 76. Southwest wind 3 to 6 mph.

    Low: 76 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: A slight chance of showers, then a chance of showers and thunderstorms after 10am. Mostly sunny, with a high near 93. Southwest wind 5 to 8 mph. Chance of precipitation is 40%.

    High: 93 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72. West southwest wind around 5 mph becoming calm in the evening.

    Low: 72 °F

    Chance
    T-storms

  • Friday

    Friday: A chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 90. West southwest wind 3 to 5 mph.

    High: 90 °F

    Chance
    T-storms

  • Friday Night

    Friday Night: A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 75. Light south southeast wind.

    Low: 75 °F

    Slight Chance
    T-storms

Detailed Forecast

Tonight
A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers and thunderstorms after 4am. Patchy fog after 1am. Otherwise, mostly cloudy, with a low around 72. South southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 20%.
Tuesday
Showers and thunderstorms likely, mainly after 4pm. Patchy fog before 8am. Otherwise, partly sunny, with a high near 89. Calm wind becoming south 5 to 8 mph in the morning. Chance of precipitation is 60%.
Tuesday Night
Showers and thunderstorms likely before 4am, then a slight chance of showers. Mostly cloudy, with a low around 74. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. Southwest wind 3 to 7 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 76. Southwest wind 3 to 6 mph.
Thursday
A slight chance of showers, then a chance of showers and thunderstorms after 10am. Mostly sunny, with a high near 93. Southwest wind 5 to 8 mph. Chance of precipitation is 40%.
Thursday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72. West southwest wind around 5 mph becoming calm in the evening.
Friday
A chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 90. West southwest wind 3 to 5 mph.
Friday Night
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 75. Light south southeast wind.
Saturday
A chance of showers and thunderstorms. Partly sunny, with a high near 93. Calm wind becoming south southwest 5 to 7 mph in the morning.
Saturday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 76. South wind 3 to 5 mph.
Sunday
A chance of showers and thunderstorms. Mostly sunny, with a high near 94. Southwest wind 3 to 6 mph.
Sunday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 74. South southwest wind 3 to 5 mph.
Monday
A chance of showers and thunderstorms. Mostly sunny, with a high near 92. South southwest wind 5 to 7 mph.
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ABOUT THIS FORECAST

 
Point Forecast:
Nason IL
 38.18°N 88.98°W
Last Update:
5:18 pm CDT Jul 14, 2025
Forecast Valid:
8pm CDT Jul 14, 2025-6pm CDT Jul 21, 2025
 
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Additional Resources

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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