Current conditions at
Southern Illinois Airport (KMDH)
Lat: 37.78°NLon: 89.25°WElev: 400ft.
Fair
38°F
3°C
| Humidity | 70% |
| Wind Speed | Calm |
| Barometer | 30.09 in (1018.9 mb) |
| Dewpoint | 29°F (-2°C) |
| Visibility | 10.00 mi |
| Last update | 14 Feb 2:52 am CST |
Extended Forecast for
Saint Johns IL
Overnight
Low: 38 °F
Mostly Cloudy
Saturday
High: 52 °F
Rain Likely
then RainSaturday Night
Low: 48 °F
Rain
Sunday
High: 57 °F
Chance Rain
then Mostly
SunnySunday Night
Low: 37 °F
Mostly Clear
Washington's Birthday
High: 61 °F
Mostly Sunny
Monday Night
Low: 45 °F
Mostly Cloudy
Tuesday
High: 64 °F
Mostly Cloudy
Tuesday Night
Low: 56 °F
Mostly Cloudy
and Breezy
Detailed Forecast
Overnight
Mostly cloudy, with a low around 38. Light south southeast wind.
Saturday
Rain, mainly after 11am. High near 52. Light and variable wind becoming east 5 to 9 mph in the morning. Chance of precipitation is 100%.
Saturday Night
Rain. Steady temperature around 48. East wind 7 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 100%.
Sunday
A 50 percent chance of rain, mainly before 9am. Cloudy, then gradually becoming mostly sunny, with a high near 57. North northeast wind 7 to 10 mph.
Sunday Night
Mostly clear, with a low around 37. North wind around 5 mph becoming calm in the evening.
Washington's Birthday
Mostly sunny, with a high near 61. Calm wind becoming south 5 to 8 mph in the morning.
Monday Night
Mostly cloudy, with a low around 45. South wind around 6 mph.
Tuesday
Mostly cloudy, with a high near 64. South wind 7 to 17 mph, with gusts as high as 26 mph.
Tuesday Night
Mostly cloudy, with a low around 56. Breezy, with a south southwest wind 16 to 20 mph, with gusts as high as 30 mph.
Wednesday
Partly sunny, with a high near 71. West southwest wind 9 to 15 mph, with gusts as high as 25 mph.
Wednesday Night
Partly cloudy, with a low around 49. Southwest wind around 8 mph.
Thursday
A chance of rain. Mostly sunny, with a high near 70. South wind 7 to 13 mph, with gusts as high as 22 mph.
Thursday Night
A slight chance of rain and thunderstorms. Mostly cloudy, with a low around 44. West southwest wind 9 to 11 mph, with gusts as high as 20 mph.
Friday
Partly sunny, with a high near 58. West wind 8 to 11 mph, with gusts as high as 18 mph.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast AreaABOUT THIS FORECAST
Point Forecast:
Saint Johns IL
38.03°N 89.24°W
38.03°N 89.24°W
3:16 am CST Feb 14, 2026
3am CST Feb 14, 2026-6pm CST Feb 20, 2026
Additional Resources
Radar & Satellite Image
Hourly Weather Forecast
