Current conditions at

Mount Vernon Airport (KMVN)

Lat: 38.33° N Lon: 88.85° W Elev: 466 ft.

Partly Cloudy

76°F

24°C

Humidity 91%
Wind Speed Calm
Barometer 29.96 in (1014.4 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index76°F (24°C)
Last update 19 Jul 10:56 pm CDT
Detailed forecast for

Jefferson County

Tonight
Partly cloudy this evening, then becoming mostly clear. Patchy fog after midnight. Lows around 70. Northeast winds around 5 mph this evening, becoming light and variable.
Monday
Patchy fog in the morning. Mostly sunny. Highs in the lower 90s. Calm winds.
Monday Night
Mostly clear. Lows in the mid 70s. South winds around 5 mph.
Tuesday
Mostly sunny with a chance of showers. A chance of thunderstorms in the afternoon. Hot with highs in the mid 90s. West winds 5 to 10 mph. Chance of rain 50 percent. Highest heat index readings heat index readings up to 106 in the afternoon.
Tuesday Night
Mostly clear. Lows around 70. North winds 5 to 10 mph.
Wednesday
Sunny. Highs in the lower 80s.
Wednesday Night Through Thursday Night
Partly cloudy. Lows in the lower 60s. Highs in the lower 80s.
Friday
Partly sunny. Highs in the lower 80s.
Friday Night
Mostly cloudy with a chance of showers. Lows in the mid 60s. Chance of rain 30 percent.
Saturday
Mostly sunny. Highs in the upper 80s.
Saturday Night
Mostly clear. Lows in the upper 60s.
Sunday
Mostly sunny. Highs in the lower 90s.



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1142 PM CDT Sun Jul 19 2026
 
 

Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database