Heat Persists in the Southwest; Elevated to Critical Fire Weather in the Great Basin; Poor Air Quality in the West

Dangerous heat will persist across the Southwest U.S. through this week, easing by next week. The heat will focus further east in the Great Plains and Mississippi Valley beginning next week. Elevated to locally critical fire weather conditions will persist for the Great Basin today. Poor air quality lingers for the Northwest, Great Basin, Central Rockies into the Plains. Read More >

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Fog/Mist

64°F

18°C

Humidity 97%
Wind Speed Calm
Barometer 30.04 in
Dewpoint 64°F (18°C)
Visibility 5.00 mi
Last update 4 Aug 6:35 am CDT
Extended Forecast for

Marine IL

  • Today

    Today: Patchy fog before 7am.  Otherwise, sunny, with a high near 86. Calm wind.

    High: 86 °F

    Patchy Fog
    then Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 66. Light southeast wind.

    Low: 66 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 89. Calm wind becoming south around 6 mph in the morning.

    High: 89 °F

    Sunny

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am.  Mostly cloudy, with a low around 70. Southeast wind 3 to 6 mph.  Chance of precipitation is 70%.

    Low: 70 °F

    Slight Chance
    T-storms then
    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm before 1pm.  High near 85. South wind 3 to 6 mph.  Chance of precipitation is 80%.

    High: 85 °F

    Showers

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am.  Mostly cloudy, with a low around 69.

    Low: 69 °F

    Chance
    T-storms

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm.  Partly sunny, with a high near 86.

    High: 86 °F

    Partly Sunny
    then Slight
    Chance
    T-storms

  • Friday Night

    Friday Night: A 30 percent chance of showers and thunderstorms.  Mostly cloudy, with a low around 69.

    Low: 69 °F

    Chance
    T-storms

  • Saturday

    Saturday: Mostly sunny, with a high near 88.

    High: 88 °F

    Mostly Sunny

Detailed Forecast

Today
Patchy fog before 7am. Otherwise, sunny, with a high near 86. Calm wind.
Tonight
Mostly clear, with a low around 66. Light southeast wind.
Wednesday
Sunny, with a high near 89. Calm wind becoming south around 6 mph in the morning.
Wednesday Night
A slight chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 70. Southeast wind 3 to 6 mph. Chance of precipitation is 70%.
Thursday
Showers and possibly a thunderstorm before 1pm. High near 85. South wind 3 to 6 mph. Chance of precipitation is 80%.
Thursday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 69.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 86.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 69.
Saturday
Mostly sunny, with a high near 88.
Saturday Night
Mostly clear, with a low around 71.
Sunday
Sunny, with a high near 90.
Sunday Night
Mostly clear, with a low around 73.
Monday
Mostly sunny, with a high near 92.
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ABOUT THIS FORECAST

 
Point Forecast:
Marine IL
 38.78°N 89.77°W (Elev. 512 ft)
5:21 am CDT Aug 4, 2026
6am CDT Aug 4, 2026-6pm CDT Aug 10, 2026
 
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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