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

Hazardous Weather Conditions

Current conditions at

St. Louis Lambert International Airport (KSTL)

Lat: 38.75°NLon: 90.37°WElev: 604ft.

Fair

86°F

30°C

Humidity 67%
Wind Speed S 10 mph
Barometer 29.99 in (1014.0 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index94°F (34°C)
Last update 30 Jun 10:51 pm CDT
Extended Forecast for

Saint John MO

Extreme Heat Warning June 30, 11:08pm until July 3, 10:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning June 30, 11:08pm until July 3, 10:00pm

    NOW until 10:00pm Fri

    Extreme Heat Warning

  • Tonight

    Low: 78 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny and hot, with a high near 97. Heat index values as high as 105. South wind 5 to 8 mph.

    High: 97 °F

    Hot

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 79. South wind 6 to 9 mph.

    Low: 79 °F

    Mostly Clear

  • Thursday

    Thursday: A 20 percent chance of showers and thunderstorms after 1pm. Sunny and hot, with a high near 98. Heat index values as high as 107. Southwest wind around 6 mph.

    High: 98 °F

    Sunny then
    Slight Chance
    T-storms

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 78. South wind 3 to 7 mph.

    Low: 78 °F

    Mostly Clear

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm. Sunny and hot, with a high near 97.

    High: 97 °F

    Sunny then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 77.

    Low: 77 °F

    Chance
    T-storms

  • Independence Day

    Independence Day: A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 95.

    High: 95 °F

    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

Tonight
Mostly clear, with a low around 78. Southwest wind 6 to 8 mph.
Wednesday
Sunny and hot, with a high near 97. Heat index values as high as 105. South wind 5 to 8 mph.
Wednesday Night
Mostly clear, with a low around 79. South wind 6 to 9 mph.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny and hot, with a high near 98. Heat index values as high as 107. Southwest wind around 6 mph.
Thursday Night
Mostly clear, with a low around 78. South wind 3 to 7 mph.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny and hot, with a high near 97.
Friday Night
A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 77.
Independence Day
A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 95.
Saturday Night
A 30 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 76.
Sunday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 94.
Sunday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Monday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 92.
Monday Night
A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 74.
Tuesday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 91.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Saint John MO
 38.71°N 90.34°W (Elev. 597 ft)
Last Update:
8:36 pm CDT Jun 30, 2026
Forecast Valid:
11pm CDT Jun 30, 2026-6pm CDT Jul 7, 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