Current conditions at
Southern Illinois Airport (KMDH)
Lat: 37.78°NLon: 89.25°WElev: 400ft.
Fair
29°F
-2°C
| Humidity | 69% |
| Wind Speed | SW 9 mph |
| Barometer | 30.41 in (1030.0 mb) |
| Dewpoint | 20°F (-7°C) |
| Visibility | 10.00 mi |
| Wind Chill | 21°F (-6°C) |
| Last update | 12 Jan 3:52 am CST |
Extended Forecast for
Saint Johns IL
Today
High: 51 °F
Sunny
Tonight
Low: 34 °F
Mostly Clear
Tuesday
High: 61 °F
Increasing
CloudsTuesday Night
Low: 40 °F
Chance
ShowersWednesday
High: 44 °F
Mostly Cloudy
then Slight
Chance
Rain/SnowWednesday Night
Low: 18 °F
Mostly Cloudy
Thursday
High: 32 °F
Sunny
Thursday Night
Low: 24 °F
Mostly Cloudy
Friday
High: 43 °F
Partly Sunny
Detailed Forecast
Today
Sunny, with a high near 51. Southwest wind 7 to 13 mph, with gusts as high as 21 mph.
Tonight
Mostly clear, with a low around 34. South southwest wind 6 to 9 mph.
Tuesday
Increasing clouds, with a high near 61. Southwest wind 10 to 14 mph, with gusts as high as 21 mph.
Tuesday Night
A 30 percent chance of showers, mainly before midnight. Mostly cloudy, with a low around 40. Southwest wind 6 to 9 mph becoming northwest after midnight.
Wednesday
A slight chance of rain showers after noon, mixing with snow after 3pm. Mostly cloudy, with a high near 44. Northwest wind 9 to 18 mph, with gusts as high as 28 mph. Chance of precipitation is 20%.
Wednesday Night
Mostly cloudy, with a low around 18. North northwest wind 13 to 18 mph, with gusts as high as 28 mph.
Thursday
Sunny, with a high near 32. North northwest wind 6 to 13 mph, with gusts as high as 20 mph.
Thursday Night
Mostly cloudy, with a low around 24. South southwest wind 5 to 10 mph, with gusts as high as 18 mph.
Friday
Partly sunny, with a high near 43. West wind 10 to 14 mph, with gusts as high as 23 mph.
Friday Night
Mostly cloudy, with a low around 22. West wind 8 to 10 mph.
Saturday
Partly sunny, with a high near 33. West northwest wind 9 to 13 mph, with gusts as high as 21 mph.
Saturday Night
Partly cloudy, with a low around 12. West northwest wind 8 to 10 mph.
Sunday
Sunny, with a high near 29. West northwest wind 9 to 13 mph, with gusts as high as 20 mph.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast AreaABOUT THIS FORECAST
Point Forecast:
Saint Johns IL
38.06°N 89.24°W
38.06°N 89.24°W
3:16 am CST Jan 12, 2026
4am CST Jan 12, 2026-6pm CST Jan 18, 2026
Additional Resources
Radar & Satellite Image
Hourly Weather Forecast
