Upper Alton, IL Weather Forecast
Local 7-day forecast
Patchy Fog then Mostly Sunny
Track current conditions, temperature changes, wind, and the full daily outlook for Upper Alton, IL in one place.
Patchy fog before 9am. Mostly sunny, with a high near 85. East wind 0 to 5 mph.
Local Weather Overview
This forecast page for Upper Alton, 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: Aug 23, 2026 4:32 PM CDT.
The active forecast window currently covers Aug 24 to Aug 29, 2026 for Upper Alton, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Aug 24 to Aug 29, 2026
- Latest sync
- Aug 23, 2026 4:32 PM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in Upper Alton
Wednesday looks like the warmest upcoming period in Upper Alton at 91 degrees F.
Monday Night is the coolest period ahead with temperatures near 62 degrees F.
The strongest winds are forecast for Thursday at about 3 to 9 mph NW.
Precipitation is mentioned in 3 upcoming forecast periods.
Forecast Details
- Last updated
- Aug 23, 2026 4:32 PM 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
Mostly clear, with a low around 62. East wind around 5 mph.
Sunny, with a high near 87. Southeast wind 3 to 7 mph.
Partly cloudy, with a low around 67.
Mostly sunny, with a high near 91.
A slight chance of showers and thunderstorms between 7pm and 1am. Partly cloudy, with a low around 67. Chance of precipitation is 20%.
Sunny, with a high near 89.
Mostly clear, with a low around 65.
Sunny, with a high near 88.
Partly cloudy, with a low around 67.
A slight chance of rain showers between 7am and 1pm. Mostly sunny, with a high near 89. Chance of precipitation is 20%.
A slight chance of showers and thunderstorms between 7pm and 1am, then a chance of showers and thunderstorms. Partly cloudy, with a low around 71. Chance of precipitation is 30%.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Monday
Aug 24
|
Patchy Fog then Mostly Sunny
|
85°F |
0 to 5 mph
E
|
|
Monday Night
Aug 24
|
Mostly Clear
|
62°F |
5 mph
E
|
|
Tuesday
Aug 25
|
Sunny
|
87°F |
3 to 7 mph
SE
|
|
Tuesday Night
Aug 25
|
Partly Cloudy
|
67°F |
2 to 6 mph
SE
|
|
Wednesday
Aug 26
|
Mostly Sunny
|
91°F |
2 to 7 mph
SW
|
|
Wednesday Night
Aug 26
|
Slight Chance Showers And Thunderstorms
|
67°F |
2 to 6 mph
NW
|
|
Thursday
Aug 27
|
Sunny
|
89°F |
3 to 9 mph
NW
|
|
Thursday Night
Aug 27
|
Mostly Clear
|
65°F |
1 to 8 mph
N
|
|
Friday
Aug 28
|
Sunny
|
88°F |
0 to 5 mph
N
|
|
Friday Night
Aug 28
|
Partly Cloudy
|
67°F |
5 mph
E
|
|
Saturday
Aug 29
|
Slight Chance Rain Showers
|
89°F |
5 to 9 mph
SE
|
|
Saturday Night
Aug 29
|
Slight Chance Showers And Thunderstorms
|
71°F |
8 mph
SE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Upper Alton.