Alton, IL Weather Forecast
Local 7-day forecast
Sunny
Track current conditions, temperature changes, wind, and the full daily outlook for Alton, IL in one place.
Sunny, with a high near 85. Northwest wind 5 to 8 mph.
Local Weather Overview
This forecast page for 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: Jun 10, 2026 12:16 PM CDT.
The active forecast window currently covers Jun 12 to Jun 16, 2026 for Alton, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Jun 12 to Jun 16, 2026
- Latest sync
- Jun 10, 2026 12:16 PM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in Alton
Saturday looks like the warmest upcoming period in Alton at 88 degrees F.
Monday Night is the coolest period ahead with temperatures near 60 degrees F.
The strongest winds are forecast for Sunday at about 8 to 12 mph N.
Precipitation is mentioned in 7 upcoming forecast periods.
Forecast Details
- Last updated
- Jun 10, 2026 12:16 PM CDT
- Coverage
- 5 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 65.
A chance of showers and thunderstorms between 7am and 1pm, then a slight chance of showers and thunderstorms. Mostly sunny, with a high near 88. Chance of precipitation is 40%.
A slight chance of showers and thunderstorms before 7pm, then showers and thunderstorms likely. Mostly cloudy, with a low around 69. Chance of precipitation is 70%.
Showers and thunderstorms likely before 1pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 82. Chance of precipitation is 70%.
A chance of showers and thunderstorms. Mostly cloudy, with a low around 62. Chance of precipitation is 30%.
A chance of rain showers before 1pm, then a slight chance of showers and thunderstorms. Partly sunny, with a high near 78. Chance of precipitation is 30%.
A slight chance of showers and thunderstorms before 7pm. Partly cloudy, with a low around 60. Chance of precipitation is 20%.
A slight chance of showers and thunderstorms between 7am and 1pm. Mostly sunny, with a high near 80. Chance of precipitation is 20%.
Partly cloudy, with a low around 62.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Friday
Jun 12
|
Sunny
|
85°F |
5 to 8 mph
NW
|
|
Friday Night
Jun 12
|
Mostly Clear
|
65°F |
0 to 5 mph
E
|
|
Saturday
Jun 13
|
Chance Showers And Thunderstorms
|
88°F |
2 to 10 mph
S
|
|
Saturday Night
Jun 13
|
Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely
|
69°F |
6 to 9 mph
SW
|
|
Sunday
Jun 14
|
Showers And Thunderstorms Likely
|
82°F |
8 to 12 mph
N
|
|
Sunday Night
Jun 14
|
Chance Showers And Thunderstorms
|
62°F |
5 to 12 mph
NE
|
|
Monday
Jun 15
|
Chance Rain Showers then Slight Chance Showers And Thunderstorms
|
78°F |
5 to 9 mph
N
|
|
Monday Night
Jun 15
|
Slight Chance Showers And Thunderstorms then Partly Cloudy
|
60°F |
2 to 8 mph
NW
|
|
Tuesday
Jun 16
|
Slight Chance Showers And Thunderstorms
|
80°F |
5 to 10 mph
W
|
|
Tuesday Night
Jun 16
|
Partly Cloudy
|
62°F |
3 to 8 mph
W
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Alton.
