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

Hazardous Weather Conditions

Current conditions at

St. Charles, St. Charles County Smartt Airport (KSET)

Lat: 38.93°NLon: 90.43°WElev: 436ft.

Fair

72°F

22°C

Humidity 52%
Wind Speed W 14 mph
Barometer 30.03 in (1016.4 mb)
Dewpoint 53°F (12°C)
Visibility 10.00 mi
Last update 22 Apr 12:54 pm CDT
Extended Forecast for

Grafton IL

Flood Warning April 22, 01:30pm until April 30, 07:00am
Click here for hazard details and duration
Flood Warning
  •  
    Flood Warning April 22, 01:30pm until April 30, 07:00am

    NOW until 7:00am Thu

    Flood Warning

  • This Afternoon

    High: 75 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 59. Southwest wind around 7 mph becoming south in the evening.

    Low: 59 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 82. South wind 7 to 16 mph, with gusts as high as 28 mph.

    High: 82 °F

    Sunny

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 62. South wind 11 to 15 mph, with gusts as high as 24 mph. Chance of precipitation is 70%.

    Low: 62 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers and possibly a thunderstorm. High near 74. South wind around 10 mph becoming west in the afternoon. Chance of precipitation is 80%.

    High: 74 °F

    Showers

  • Friday Night

    Friday Night: A 20 percent chance of showers before 1am. Partly cloudy, with a low around 52.

    Low: 52 °F

    Slight Chance
    Showers

  • Saturday

    Saturday: Sunny, with a high near 75.

    High: 75 °F

    Sunny

  • Saturday Night

    Saturday Night: A 20 percent chance of showers before 1am. Partly cloudy, with a low around 54.

    Low: 54 °F

    Slight Chance
    Showers

Detailed Forecast

This Afternoon
Sunny, with a high near 75. Southwest wind around 10 mph.
Tonight
Mostly clear, with a low around 59. Southwest wind around 7 mph becoming south in the evening.
Thursday
Sunny, with a high near 82. South wind 7 to 16 mph, with gusts as high as 28 mph.
Thursday Night
Showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 62. South wind 11 to 15 mph, with gusts as high as 24 mph. Chance of precipitation is 70%.
Friday
Showers and possibly a thunderstorm. High near 74. South wind around 10 mph becoming west in the afternoon. Chance of precipitation is 80%.
Friday Night
A 20 percent chance of showers before 1am. Partly cloudy, with a low around 52.
Saturday
Sunny, with a high near 75.
Saturday Night
A 20 percent chance of showers before 1am. Partly cloudy, with a low around 54.
Sunday
A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 74.
Sunday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 62. Chance of precipitation is 70%.
Monday
Showers and possibly a thunderstorm. High near 77. Chance of precipitation is 80%.
Monday Night
A 30 percent chance of showers. Partly cloudy, with a low around 51.
Tuesday
Mostly sunny, with a high near 70.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Grafton IL
 38.98°N 90.42°W (Elev. 673 ft)
Last Update:
1:26 pm CDT Apr 22, 2026
Forecast Valid:
1pm CDT Apr 22, 2026-6pm CDT Apr 28, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

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