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

An Active Weather Wednesday

Strong to severe thunderstorms are possible on Wednesday in parts of the Ohio Valley, Upper Mississippi Valley and south-central Plains. These storms may produce heavy rain and flooding in the Ohio Valley. Meanwhile, a strong cold front will sweep through the Northwest U.S. with rain, mountain snow and high winds. Finally, heat and record high temperatures are likely across the Southern U.S. Read More >

Hazardous Weather Conditions

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Partly Cloudy

68°F

20°C

Humidity 67%
Wind Speed S 8 mph
Barometer 29.87 in
Dewpoint 57°F (14°C)
Visibility 10.00 mi
Last update 18 May 4:35 am CDT
Extended Forecast for

Alton ILSimilar City Names

  • Overnight

    Overnight: A 30 percent chance of showers and thunderstorms. Cloudy, with a low around 64. South wind around 7 mph.

    Chance
    T-storms

    Low: 64 °F

  • Wednesday

    Wednesday: Showers and thunderstorms before noon, then a slight chance of showers and thunderstorms after 3pm. Some of the storms could produce heavy rainfall. High near 79. South wind 8 to 10 mph becoming west in the afternoon. Chance of precipitation is 90%.

    Heavy Rain
    then Slight
    Chance
    T-storms

    High: 79 °F

  • Wednesday
    Night

    Wednesday Night: Partly cloudy, with a low around 64. Northwest wind 3 to 8 mph.

    Partly Cloudy

    Low: 64 °F

  • Thursday

    Thursday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. Light south wind increasing to 9 to 14 mph in the morning.

    Mostly Sunny
    then Slight
    Chance
    T-storms

    High: 87 °F

  • Thursday
    Night

    Thursday Night: Mostly clear, with a low around 72. South wind around 11 mph.

    Mostly Clear

    Low: 72 °F

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 89.

    Mostly Sunny
    then Slight
    Chance
    T-storms

    High: 89 °F

  • Friday
    Night

    Friday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 62. Chance of precipitation is 70%.

    Showers
    Likely

    Low: 62 °F

  • Saturday

    Saturday: Showers and possibly a thunderstorm. High near 68. Chance of precipitation is 80%.

    Showers

    High: 68 °F

  • Saturday
    Night

    Saturday Night: A 50 percent chance of showers, mainly before 1am. Mostly cloudy, with a low around 49.

    Chance
    Showers

    Low: 49 °F

Detailed Forecast

Overnight
A 30 percent chance of showers and thunderstorms. Cloudy, with a low around 64. South wind around 7 mph.
Wednesday
Showers and thunderstorms before noon, then a slight chance of showers and thunderstorms after 3pm. Some of the storms could produce heavy rainfall. High near 79. South wind 8 to 10 mph becoming west in the afternoon. Chance of precipitation is 90%.
Wednesday Night
Partly cloudy, with a low around 64. Northwest wind 3 to 8 mph.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. Light south wind increasing to 9 to 14 mph in the morning.
Thursday Night
Mostly clear, with a low around 72. South wind around 11 mph.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 89.
Friday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 62. Chance of precipitation is 70%.
Saturday
Showers and possibly a thunderstorm. High near 68. Chance of precipitation is 80%.
Saturday Night
A 50 percent chance of showers, mainly before 1am. Mostly cloudy, with a low around 49.
Sunday
Mostly sunny, with a high near 67.
Sunday Night
Partly cloudy, with a low around 51.
Monday
Mostly sunny, with a high near 71.
Monday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 57.
Tuesday
A 30 percent chance of showers. Partly sunny, with a high near 75.
Click Map For Forecast
Disclaimer
Map Legend
Point Forecast:
Alton ILSimilar City Names
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
4:26 am CDT May 18, 2022
Forecast Valid:
4am CDT May 18, 2022-6pm CDT May 24, 2022
 
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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