Alton, IL Weather Forecast
Local 7-day forecast
Rain Showers Likely
Track current conditions, temperature changes, wind, and the full daily outlook for Alton, IL in one place.
Rain showers likely before 1pm, then showers and thunderstorms likely. Cloudy. High near 70, with temperatures falling to around 66 in the afternoon. West wind around 10 mph. Chance of precipitation is 70%.
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: Apr 9, 2026 4:28 PM CDT.
The active forecast window currently covers Apr 10 to Apr 15, 2026 for Alton, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Apr 10 to Apr 15, 2026
- Latest sync
- Apr 9, 2026 4:28 PM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in Alton
Tuesday looks like the warmest upcoming period in Alton at 86 degrees F.
Friday Night is the coolest period ahead with temperatures near 50 degrees F.
The strongest winds are forecast for Sunday at about 8 to 20 mph S.
Precipitation is mentioned in 12 upcoming forecast periods.
Forecast Details
- Last updated
- Apr 9, 2026 4:28 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
A chance of rain showers. Mostly cloudy, with a low around 50. Northeast wind 5 to 8 mph. Chance of precipitation is 30%.
A chance of rain showers before 1pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 73. Southeast wind 6 to 10 mph. Chance of precipitation is 40%.
A chance of showers and thunderstorms before 7pm. Mostly cloudy, with a low around 60. Chance of precipitation is 30%.
A chance of rain showers after 1pm. Mostly cloudy, with a high near 79. Chance of precipitation is 30%.
A chance of rain showers before 7pm, then showers and thunderstorms likely. Mostly cloudy, with a low around 63. Chance of precipitation is 60%.
Showers and thunderstorms likely before 1pm, then a slight chance of showers and thunderstorms. Mostly cloudy, with a high near 84. Chance of precipitation is 60%.
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 68. Chance of precipitation is 20%.
A chance of showers and thunderstorms. Partly sunny, with a high near 86. Chance of precipitation is 40%.
A chance of showers and thunderstorms before 1am, then showers and thunderstorms likely. Mostly cloudy, with a low around 65. Chance of precipitation is 60%.
Showers and thunderstorms likely before 1pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 81. Chance of precipitation is 60%.
A chance of showers and thunderstorms before 7pm, then a chance of showers and thunderstorms. Mostly cloudy, with a low around 57. Chance of precipitation is 40%.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Friday
Apr 10
|
Rain Showers Likely
|
70°F |
10 mph
W
|
|
Friday Night
Apr 10
|
Chance Rain Showers
|
50°F |
5 to 8 mph
NE
|
|
Saturday
Apr 11
|
Chance Rain Showers
|
73°F |
6 to 10 mph
SE
|
|
Saturday Night
Apr 11
|
Chance Showers And Thunderstorms then Mostly Cloudy
|
60°F |
9 mph
SE
|
|
Sunday
Apr 12
|
Mostly Cloudy then Chance Rain Showers
|
79°F |
8 to 20 mph
S
|
|
Sunday Night
Apr 12
|
Showers And Thunderstorms Likely
|
63°F |
12 to 16 mph
S
|
|
Monday
Apr 13
|
Showers And Thunderstorms Likely
|
84°F |
10 to 16 mph
SW
|
|
Monday Night
Apr 13
|
Slight Chance Showers And Thunderstorms
|
68°F |
10 to 15 mph
S
|
|
Tuesday
Apr 14
|
Chance Showers And Thunderstorms
|
86°F |
10 to 17 mph
SW
|
|
Tuesday Night
Apr 14
|
Chance Showers And Thunderstorms
|
65°F |
12 to 15 mph
S
|
|
Wednesday
Apr 15
|
Showers And Thunderstorms Likely
|
81°F |
12 to 17 mph
SW
|
|
Wednesday Night
Apr 15
|
Chance Showers And Thunderstorms
|
57°F |
6 to 12 mph
SW
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Alton.
