Illiopolis, IL Weather Forecast
Local 7-day forecast
Mostly Clear
Track current conditions, temperature changes, wind, and the full daily outlook for Illiopolis, IL in one place.
Mostly clear, with a low around 55. Northeast wind around 8 mph.
Local Weather Overview
This forecast page for Illiopolis, IL is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Jun 2, 2026 6:28 AM CDT.
The active forecast window currently covers Jun 2 to Jun 8, 2026 for Illiopolis, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Jun 2 to Jun 8, 2026
- Latest sync
- Jun 2, 2026 6:28 AM CDT
- Forecast office
- ILX
- Source
- NOAA / NWS
Daily Outlook
This Week in Illiopolis
Sunday looks like the warmest upcoming period in Illiopolis at 87 degrees F.
Tuesday Night is the coolest period ahead with temperatures near 53 degrees F.
The strongest winds are forecast for Friday at about 10 to 15 mph SSW.
Precipitation is mentioned in 6 upcoming forecast periods.
Forecast Details
- Last updated
- Jun 2, 2026 6:28 AM CDT
- Coverage
- 7 days
- Time zone
- America/Chicago
- Forecast office
- ILX
- Radar station
- KILX
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
Sunny, with a high near 82. East northeast wind 7 to 13 mph, with gusts as high as 17 mph.
Mostly clear, with a low around 53. East northeast wind 5 to 12 mph, with gusts as high as 16 mph.
Sunny, with a high near 82. East southeast wind around 8 mph.
Mostly clear, with a low around 58. South southeast wind 5 to 8 mph.
Sunny, with a high near 85. South wind 7 to 13 mph, with gusts as high as 17 mph.
Partly cloudy, with a low around 63. South wind around 12 mph, with gusts as high as 18 mph.
Mostly sunny, with a high near 85.
A chance of showers and thunderstorms after 7pm. Mostly cloudy, with a low around 66. Chance of precipitation is 50%.
A chance of showers and thunderstorms. Partly sunny, with a high near 86.
A chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
A chance of rain showers before 1pm, then a chance of showers and thunderstorms. Partly sunny, with a high near 87.
A chance of showers and thunderstorms before 7pm, then a chance of showers and thunderstorms. Mostly cloudy, with a low around 67.
A chance of rain showers before 1pm, then a chance of showers and thunderstorms. Partly sunny, with a high near 86.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Overnight
Jun 2
|
Mostly Clear
|
55°F |
8 mph
NE
|
|
Tuesday
Jun 2
|
Sunny
|
82°F |
7 to 13 mph
ENE
|
|
Tuesday Night
Jun 2
|
Mostly Clear
|
53°F |
5 to 12 mph
ENE
|
|
Wednesday
Jun 3
|
Sunny
|
82°F |
8 mph
ESE
|
|
Wednesday Night
Jun 3
|
Mostly Clear
|
58°F |
5 to 8 mph
SSE
|
|
Thursday
Jun 4
|
Sunny
|
85°F |
7 to 13 mph
S
|
|
Thursday Night
Jun 4
|
Partly Cloudy
|
63°F |
12 mph
S
|
|
Friday
Jun 5
|
Mostly Sunny
|
85°F |
10 to 15 mph
SSW
|
|
Friday Night
Jun 5
|
Chance Showers And Thunderstorms
|
66°F |
9 to 14 mph
S
|
|
Saturday
Jun 6
|
Chance Showers And Thunderstorms
|
86°F |
13 mph
SSW
|
|
Saturday Night
Jun 6
|
Chance Showers And Thunderstorms
|
66°F |
6 to 12 mph
SSW
|
|
Sunday
Jun 7
|
Chance Rain Showers
|
87°F |
6 to 10 mph
S
|
|
Sunday Night
Jun 7
|
Chance Showers And Thunderstorms
|
67°F |
7 to 10 mph
SE
|
|
Monday
Jun 8
|
Chance Rain Showers
|
86°F |
9 to 13 mph
SE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Illiopolis.