Saint Clair County, IL Weather Forecast
County weather hub
Chance Showers And Thunderstorms
Compare major city weather across Saint Clair County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
A chance of showers and thunderstorms. Partly sunny, with a high near 89. Heat index values as high as 100. Southwest wind around 7 mph. Chance of precipitation is 40%.
County Weather Overview
This county weather page brings together forecast coverage for Saint Clair County so visitors can compare temperatures, wind, and conditions across the region without hopping between unrelated pages.
Current forecast coverage spans 15 of 15 mapped cities in Saint Clair County.
Page Snapshot
- Page focus
- county weather
- Forecast window
- Jul 10 to Jul 15, 2026
- Latest sync
- Jul 9, 2026 12:48 AM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in Saint Clair County
Wednesday looks like the warmest upcoming period in Saint Clair County at 91 degrees F.
Sunday Night is the coolest period ahead with temperatures near 68 degrees F.
The strongest winds are forecast for Monday at about 3 to 8 mph NE.
Precipitation is mentioned in 6 upcoming forecast periods.
Forecast Details
- Last updated
- Jul 9, 2026 12:48 AM CDT
- Coverage
- 6 days
- Time zone
- America/Chicago
- Forecast office
- LSX
- Radar station
- KLSX
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
Showers and thunderstorms likely before 1am, then showers and thunderstorms likely. Mostly cloudy, with a low around 72. West wind around 5 mph. Chance of precipitation is 70%.
Showers and thunderstorms likely before 1pm, then a chance of showers and thunderstorms. Partly sunny, with a high near 87. Chance of precipitation is 60%.
A chance of showers and thunderstorms before 7pm, then a chance of showers and thunderstorms. Partly cloudy, with a low around 69. Chance of precipitation is 50%.
A slight chance of rain showers before 1pm, then a chance of showers and thunderstorms. Mostly sunny, with a high near 86. Chance of precipitation is 30%.
A chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 68. Chance of precipitation is 30%.
Sunny, with a high near 88.
Mostly clear, with a low around 70.
Sunny, with a high near 90.
Mostly clear, with a low around 71.
Sunny, with a high near 91.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Friday
Jul 10
|
Chance Showers And Thunderstorms
|
89°F |
7 mph
SW
|
|
Friday Night
Jul 10
|
Showers And Thunderstorms Likely
|
72°F |
5 mph
W
|
|
Saturday
Jul 11
|
Showers And Thunderstorms Likely
|
87°F |
6 mph
NW
|
|
Saturday Night
Jul 11
|
Chance Showers And Thunderstorms
|
69°F |
5 mph
NE
|
|
Sunday
Jul 12
|
Chance Showers And Thunderstorms
|
86°F |
3 to 7 mph
NE
|
|
Sunday Night
Jul 12
|
Chance Showers And Thunderstorms then Mostly Clear
|
68°F |
2 to 7 mph
NE
|
|
Monday
Jul 13
|
Sunny
|
88°F |
3 to 8 mph
NE
|
|
Monday Night
Jul 13
|
Mostly Clear
|
70°F |
1 to 8 mph
NE
|
|
Tuesday
Jul 14
|
Sunny
|
90°F |
2 to 6 mph
NE
|
|
Tuesday Night
Jul 14
|
Mostly Clear
|
71°F |
0 to 5 mph
S
|
|
Wednesday
Jul 15
|
Sunny
|
91°F |
1 to 5 mph
S
|
Major City Forecasts
Live forecast snapshots for major cities across Saint Clair County.
Coverage
Forecast coverage currently spans 15 of 15 mapped cities in Saint Clair County.
Largest mapped city population in this region: 40,536.
