Weather for Alton, Illinois
Current Weather
Humidity: 55%
Feels Like: 87.7°F
Wind: WSW 6.3 mph
Wind Gusts: 7.2 mph
Precipitation: 0 in
Cloud Cover: 0%
Visibility: 9 mi
UV Index: 5
Five Day Weather Forecast
Sat
H: 98°F
L: 66°F
Sun
H: 91°F
L: 69°F
Mon
H: 92°F
L: 69°F
Tue
H: 94°F
L: 70°F
Wed
H: 94°F
L: 68°F
Air Quality
Nitrogen Dioxide: 5.37 μg/m3
Sulphur Dioxide: 5.18 μg/m3
Ozone: 167 μg/m3
Astronomical
Sun Transit: 12:56 AM
Sunset: 7:11 PM
Daylight: 12 hrs 31 mins
Moon Transit: 5:50 AM
Moonset: 1:48 PM
Moon Phase: Waning Gibbous
Moon Illumination: 56.4%
Best Times for Fishing or Hunting
Major Periods
5:20 AM - 7:50 AM5:50 PM - 8:20 PM
Minor Periods
10:21 PM - 11:51 PM1:18 PM - 2:48 PM
Action Rating: 2 out of 5
Air Quality Alert issued September 12 at 3:10PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Fri September 12, 2025, 3:10 PM
Expires: Sat September 13, 2025, 8:00 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area from 10 AM to 8 PM CDT Saturday. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 13 at 1:49AM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Sat September 13, 2025, 1:49 AM
Expires: Sun September 14, 2025, 2:00 AM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area from 10 AM this morning to 8 PM CDT this evening. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 12 at 3:10PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Fri September 12, 2025, 3:10 PM
Expires: Sat September 13, 2025, 8:00 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area from 10 AM to 8 PM CDT Saturday. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 12 at 3:10PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Fri September 12, 2025, 3:10 PM
Expires: Sat September 13, 2025, 8:00 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area from 10 AM to 8 PM CDT Saturday. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 13 at 1:49AM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Sat September 13, 2025, 1:49 AM
Expires: Sun September 14, 2025, 2:00 AM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area from 10 AM this morning to 8 PM CDT this evening. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Weather Forecast
Average Temperature: 81.7°F
Average Humidity: 58%
Wind: 9.4 mph
UV Index: 1.5
Air Quality
Nitrogen Dioxide: 17.38 μg/m3
Sulphur Dioxide: 7.48 μg/m3
Ozone: 116.44 μg/m3
Astronomical
Sun Transit: 12:56 AM
Sunset: 7:11 PM
Daylight: 12 hrs 31 mins
Moon Transit: 5:50 AM
Moonset: 1:48 PM
Moon Phase: Waning Gibbous
Moon Illumination: 56.4%
Best Times for Fishing or Hunting
Major Periods
5:20 AM - 7:50 AM5:50 PM - 8:20 PM
Minor Periods
10:21 PM - 11:51 PM1:18 PM - 2:48 PM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 79.3°F
Average Humidity: 67%
Wind: 9.8 mph
UV Index: 1.6
Air Quality
Nitrogen Dioxide: 31.4 μg/m3
Sulphur Dioxide: 5.08 μg/m3
Ozone: 92.76 μg/m3
Astronomical
Sun Transit: 12:55 AM
Sunset: 7:10 PM
Daylight: 12 hrs 28 mins
Moon Transit: 6:52 AM
Moonset: 2:56 PM
Moon Phase: Last Quarter
Moon Illumination: 45.1%
Best Times for Fishing or Hunting
Major Periods
6:22 AM - 8:52 AM6:52 PM - 9:22 PM
Minor Periods
12:00 AM - 12:00 AM2:26 PM - 3:56 PM
Action Rating: 4 out of 5
Weather Forecast
Average Temperature: 79.9°F
Average Humidity: 72%
Wind: 7.4 mph
UV Index: 1.5
Air Quality
Nitrogen Dioxide: 15.89 μg/m3
Sulphur Dioxide: 11.5 μg/m3
Ozone: 108.04 μg/m3
Astronomical
Sun Transit: 12:55 AM
Sunset: 7:08 PM
Daylight: 12 hrs 26 mins
Moon Transit: 7:53 AM
Moonset: 3:53 PM
Moon Phase: Last Quarter
Moon Illumination: 34.0%
Best Times for Fishing or Hunting
Major Periods
7:23 AM - 9:53 AM7:52 PM - 10:22 PM
Minor Periods
3:23 PM - 4:53 PM12:00 AM - 12:00 AM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 80.8°F
Average Humidity: 55%
Wind: 7.2 mph
UV Index: 1.5
Air Quality
Nitrogen Dioxide: 16.89 μg/m3
Sulphur Dioxide: 12.91 μg/m3
Ozone: 106.08 μg/m3
Astronomical
Sun Transit: 12:55 AM
Sunset: 7:07 PM
Daylight: 12 hrs 23 mins
Moon Transit: 8:52 AM
Moonset: 4:39 PM
Moon Phase: Last Quarter
Moon Illumination: 23.8%
Best Times for Fishing or Hunting
Major Periods
8:22 AM - 10:52 AM8:49 PM - 11:19 PM
Minor Periods
4:09 PM - 5:39 PM12:29 AM - 1:59 AM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 80.7°F
Average Humidity: 51%
Wind: 6.3 mph
UV Index: 0
Air Quality
Nitrogen Dioxide: 39.69 μg/m3
Sulphur Dioxide: 9.12 μg/m3
Ozone: 73.69 μg/m3
Astronomical
Sun Transit: 12:54 AM
Sunset: 7:05 PM
Daylight: 12 hrs 21 mins
Moon Transit: 9:47 AM
Moonset: 5:15 PM
Moon Phase: Waning Crescent
Moon Illumination: 14.9%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM9:17 AM - 11:47 AM
Minor Periods
4:45 PM - 6:15 PM1:39 AM - 3:09 AM
Action Rating: 2 out of 5