Weather for Alton, Illinois
Current Weather
Five Day Weather Forecast
Mon
H: 72°F
L: 61°F
Tue
H: 79°F
L: 57°F
Wed
H: 82°F
L: 62°F
Thu
H: 84°F
L: 67°F
Fri
H: 77°F
L: 64°F
Air Quality
Nitrogen Dioxide: 2.6 μg/m3
Sulphur Dioxide: 1.6 μg/m3
Ozone: 88 μg/m3
Astronomical
Sun Transit: 1:02 PM
Sunset: 8:30 PM
Daylight: 14 hrs 54 mins
Moon Transit: 7:44 PM
Moonset: 12:57 AM
Moon Phase: First Quarter
Moon Illumination: 49.7%
Best Times for Fishing or Hunting
Major Periods
6:51 AM - 9:21 AM7:14 PM - 9:44 PM
Minor Periods
1:30 PM - 3:00 PM12:27 AM - 1:57 AM
Action Rating: 2 out of 5
Flood Warning issued June 22 at 11:29AM CDT by NWS St Louis MO
Effective: Mon June 22, 2026, 11:29 AM
Expires: Tue June 23, 2026, 11:30 PM
...The Flood Warning continues for the following rivers in Illinois... Illinois River at Meredosia. Illinois River at La Grange LD. Illinois River at Valley City. Illinois River at Hardin. River forecasts are based on observed precipitation and forecast precipitation for the next 24 hours. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Illinois River at Hardin. * WHEN...Until further notice. * ADDITIONAL DETAILS... - At 10:30 AM CDT Monday the stage was 26.0 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 10:30 AM CDT Monday was 26.0 feet. - Forecast...The river is expected to rise to a crest of 26.8 feet Thursday morning. - Flood stage is 25.0 feet.
Motorists should not attempt to drive around barricades or drive cars through flooded areas. This product, along with additional weather and stream information, is available at https://water.noaa.gov/wfo/lsx
Flood Warning issued June 22 at 11:45AM CDT until June 25 at 9:00PM CDT by NWS St Louis MO
Effective: Mon June 22, 2026, 11:45 AM
Expires: Tue June 23, 2026, 11:45 PM
...The Flood Warning continues for the following rivers in Illinois...Missouri... Mississippi River at Clarksville. Mississippi River at Louisiana. River forecasts are based on observed precipitation and forecast precipitation for the next 24 hours. This product, along with additional weather and stream information, is available at https://water.noaa.gov/wfo/lsx * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Mississippi River at Clarksville. * WHEN...Until Thursday evening. * IMPACTS...At 25.5 feet, State Route P east of Elsberry begins flooding just east of the levee. * ADDITIONAL DETAILS... - At 11:30 AM CDT Monday the stage was 25.1 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 11:30 AM CDT Monday was 25.1 feet. - Forecast...The river is expected to rise to a crest of 25.8 feet tomorrow morning. It will then fall below flood stage Wednesday afternoon. - Flood stage is 25.0 feet.
Flood Warning issued June 22 at 11:33AM CDT until June 25 at 9:00PM CDT by NWS St Louis MO
Effective: Mon June 22, 2026, 11:33 AM
Expires: Tue June 23, 2026, 11:45 PM
...The Flood Warning continues for the following rivers in Illinois...Missouri... Mississippi River at Clarksville. Mississippi River at Louisiana. River forecasts are based on observed precipitation and forecast precipitation for the next 24 hours. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Mississippi River at Clarksville. * WHEN...Until Thursday evening. * IMPACTS...At 25.5 feet, State Route P east of Elsberry begins flooding just east of the levee. * ADDITIONAL DETAILS... - At 11:00 AM CDT Monday the stage was 25.1 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 11:00 AM CDT Monday was 25.1 feet. - Forecast...The river is expected to rise to a crest of 25.8 feet tomorrow morning. It will then fall below flood stage Wednesday afternoon. - Flood stage is 25.0 feet.
Motorists should not attempt to drive around barricades or drive cars through flooded areas. This product, along with additional weather and stream information, is available at https://water.noaa.gov/wfo/lsx
Weather Forecast
Air Quality
Nitrogen Dioxide: 8.36 μg/m3
Sulphur Dioxide: 1.5 μg/m3
Ozone: 64.08 μg/m3
Astronomical
Sun Transit: 1:02 PM
Sunset: 8:30 PM
Daylight: 14 hrs 54 mins
Moon Transit: 7:44 PM
Moonset: 12:57 AM
Moon Phase: First Quarter
Moon Illumination: 49.7%
Best Times for Fishing or Hunting
Major Periods
6:51 AM - 9:21 AM7:14 PM - 9:44 PM
Minor Periods
1:30 PM - 3:00 PM12:27 AM - 1:57 AM
Action Rating: 2 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 10.86 μg/m3
Sulphur Dioxide: 1.48 μg/m3
Ozone: 63.33 μg/m3
Astronomical
Sun Transit: 1:02 PM
Sunset: 8:30 PM
Daylight: 14 hrs 54 mins
Moon Transit: 8:26 PM
Moonset: 1:19 AM
Moon Phase: First Quarter
Moon Illumination: 61.0%
Best Times for Fishing or Hunting
Major Periods
7:34 AM - 10:04 AM7:56 PM - 10:26 PM
Minor Periods
2:32 PM - 4:02 PM12:49 AM - 2:19 AM
Action Rating: 2 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 10.02 μg/m3
Sulphur Dioxide: 1.73 μg/m3
Ozone: 67.21 μg/m3
Astronomical
Sun Transit: 1:03 PM
Sunset: 8:30 PM
Daylight: 14 hrs 54 mins
Moon Transit: 9:10 PM
Moonset: 1:44 AM
Moon Phase: First Quarter
Moon Illumination: 71.7%
Best Times for Fishing or Hunting
Major Periods
8:17 AM - 10:47 AM8:40 PM - 11:10 PM
Minor Periods
3:34 PM - 5:04 PM1:14 AM - 2:44 AM
Action Rating: 3 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 11.05 μg/m3
Sulphur Dioxide: 1.81 μg/m3
Ozone: 69.79 μg/m3
Astronomical
Sun Transit: 1:03 PM
Sunset: 8:30 PM
Daylight: 14 hrs 54 mins
Moon Transit: 9:56 PM
Moonset: 2:11 AM
Moon Phase: Waxing Gibbous
Moon Illumination: 81.2%
Best Times for Fishing or Hunting
Major Periods
9:02 AM - 11:32 AM9:26 PM - 11:56 PM
Minor Periods
4:36 PM - 6:06 PM1:41 AM - 3:11 AM
Action Rating: 2 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 31.08 μg/m3
Sulphur Dioxide: 0.68 μg/m3
Ozone: 20.25 μg/m3
Astronomical
Sun Transit: 1:03 PM
Sunset: 8:30 PM
Daylight: 14 hrs 53 mins
Moon Transit: 10:45 PM
Moonset: 2:42 AM
Moon Phase: Waxing Gibbous
Moon Illumination: 89.2%
Best Times for Fishing or Hunting
Major Periods
9:49 AM - 12:19 AM12:00 AM - 12:00 AM
Minor Periods
5:38 PM - 7:08 PM2:12 AM - 3:42 AM
Action Rating: 2 out of 5