Williamson, IL Weather Forecast
Local 7-day forecast
Clear
Track current conditions, temperature changes, wind, and the full daily outlook for Williamson, IL in one place.
Clear, with a low around 69. Northeast wind around 1 mph.
Local Weather Overview
This forecast page for Williamson, 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: Jul 15, 2026 7:33 AM CDT.
The active forecast window currently covers Jul 15 to Jul 21, 2026 for Williamson, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Jul 15 to Jul 21, 2026
- Latest sync
- Jul 15, 2026 7:33 AM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in Williamson
Monday looks like the warmest upcoming period in Williamson at 93 degrees F.
Overnight is the coolest period ahead with temperatures near 69 degrees F.
The strongest winds are forecast for Tuesday at about 7 to 14 mph NW.
Precipitation is mentioned in 6 upcoming forecast periods.
Forecast Details
- Last updated
- Jul 15, 2026 7:33 AM CDT
- Coverage
- 7 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
Sunny, with a high near 90. Northeast wind 0 to 6 mph.
Mostly clear, with a low around 71. East wind 0 to 5 mph.
A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 89. South wind 0 to 5 mph. Chance of precipitation is 30%.
A chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72. Southwest wind 0 to 3 mph. Chance of precipitation is 40%.
Showers and thunderstorms likely after 7am. Mostly sunny, with a high near 89. Chance of precipitation is 70%.
Showers and thunderstorms likely before 7pm, then a slight chance of showers and thunderstorms between 7pm and 1am. Partly cloudy, with a low around 72. Chance of precipitation is 70%.
Sunny, with a high near 91.
Mostly clear, with a low around 73.
Sunny, with a high near 91.
Mostly clear, with a low around 72.
A slight chance of showers and thunderstorms after 1pm. Sunny, with a high near 93. Chance of precipitation is 20%.
A slight chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 73. Chance of precipitation is 20%.
Mostly sunny, with a high near 88.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Overnight
Jul 15
|
Clear
|
69°F |
1 mph
NE
|
|
Wednesday
Jul 15
|
Sunny
|
90°F |
0 to 6 mph
NE
|
|
Wednesday Night
Jul 15
|
Mostly Clear
|
71°F |
0 to 5 mph
E
|
|
Thursday
Jul 16
|
Mostly Sunny then Chance Showers And Thunderstorms
|
89°F |
0 to 5 mph
S
|
|
Thursday Night
Jul 16
|
Chance Showers And Thunderstorms
|
72°F |
0 to 3 mph
SW
|
|
Friday
Jul 17
|
Showers And Thunderstorms Likely
|
89°F |
0 to 8 mph
W
|
|
Friday Night
Jul 17
|
Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms
|
72°F |
2 to 6 mph
W
|
|
Saturday
Jul 18
|
Sunny
|
91°F |
5 to 12 mph
W
|
|
Saturday Night
Jul 18
|
Mostly Clear
|
73°F |
5 to 10 mph
W
|
|
Sunday
Jul 19
|
Sunny
|
91°F |
5 to 8 mph
W
|
|
Sunday Night
Jul 19
|
Mostly Clear
|
72°F |
2 to 7 mph
S
|
|
Monday
Jul 20
|
Sunny then Slight Chance Showers And Thunderstorms
|
93°F |
5 to 10 mph
SW
|
|
Monday Night
Jul 20
|
Slight Chance Showers And Thunderstorms
|
73°F |
6 to 10 mph
W
|
|
Tuesday
Jul 21
|
Mostly Sunny
|
88°F |
7 to 14 mph
NW
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Williamson.