Weather for Byron, Illinois
Current Weather
Five Day Weather Forecast
Sun
H: 77°F
L: 41°F
Mon
H: 74°F
L: 44°F
Tue
H: 57°F
L: 47°F
Wed
H: 55°F
L: 39°F
Thu
H: 60°F
L: 37°F
Air Quality
Nitrogen Dioxide: 8.35 μg/m3
Sulphur Dioxide: 1.35 μg/m3
Ozone: 72 μg/m3
Astronomical
Sun Transit: 12:53 AM
Sunset: 7:59 PM
Daylight: 14 hrs 9 mins
Moon Transit: 2:00 AM
Moonset: 6:25 AM
Moon Phase: Full
Moon Illumination: 94.4%
Best Times for Fishing or Hunting
Major Periods
1:30 AM - 4:00 AM2:00 PM - 4:30 PM
Minor Periods
10:02 PM - 11:32 PM5:55 AM - 7:25 AM
Action Rating: 4 out of 5
Flood Warning issued May 3 at 4:26AM CDT until May 7 at 1:00AM CDT by NWS Milwaukee/Sullivan WI
Effective: Sun May 3, 2026, 4:26 AM
Expires: Sun May 3, 2026, 4:30 PM
...The Flood Warning continues for the following rivers in Wisconsin...Illinois... Rock River Near Lake Koshkonong affecting Rock and Jefferson Counties. Rock River At Fort Atkinson affecting Jefferson County. Rock River At Afton affecting Winnebago and Rock Counties. ROCK RIVER near LEBANON-3 E-HWY MM BRIDGE affecting Dodge County. ...The Flood Warning is cancelled for the following rivers in Wisconsin... Rock River At Newville affecting Rock County. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Rock River at Afton. * WHEN...Until early Thursday morning. * IMPACTS...At 10.0 feet, Floodwaters affect the property of a home on South Christian Road on the east side of the river in the Afton area. Minor erosional flood damage occurs to lowland and agricultural land adjacent to the river the Afton and Janesville areas. * ADDITIONAL DETAILS... - At 4:00 AM CDT Sunday the stage was 9.7 feet. - Bankfull stage is 8.0 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 4:00 AM CDT Sunday was 9.9 feet. - Forecast...The river is expected to fall below flood stage Wednesday evening and continue falling to 8.5 feet Saturday evening. - Flood stage is 9.0 feet. - Flood History...This crest compares to a previous crest of 9.7 feet on 04/11/1922. - http://www.weather.gov/safety/flood
Motorists should not attempt to drive around barricades or drive cars through flooded areas. Caution is urged when walking near riverbanks. Additional information is available at www.weather.gov. The next statement will be issued early this morning at 530 AM CDT.
Flood Warning issued May 3 at 10:59AM CDT until May 6 at 7:00PM CDT by NWS Milwaukee/Sullivan WI
Effective: Sun May 3, 2026, 10:59 AM
Expires: Sun May 3, 2026, 11:00 PM
...The Flood Warning continues for the following rivers in Wisconsin...Illinois... Rock River Near Lake Koshkonong affecting Jefferson and Rock Counties. Rock River At Afton affecting Rock and Winnebago Counties. Rock River At Fort Atkinson affecting Jefferson County. ROCK RIVER near LEBANON-3 E-HWY MM BRIDGE affecting Dodge County. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Rock River at Afton. * WHEN...Until Wednesday evening. * IMPACTS...At 10.0 feet, Floodwaters affect the property of a home on South Christian Road on the east side of the river in the Afton area. Minor erosional flood damage occurs to lowland and agricultural land adjacent to the river the Afton and Janesville areas. * ADDITIONAL DETAILS... - At 10:00 AM CDT Sunday the stage was 9.6 feet. - Bankfull stage is 8.0 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 10:00 AM CDT Sunday was 9.9 feet. - Forecast...The river is expected to fall below flood stage early Wednesday afternoon and continue falling to 8.3 feet Sunday, May 10. - Flood stage is 9.0 feet. - Flood History...This crest compares to a previous crest of 9.6 feet on 03/14/1985. - http://www.weather.gov/safety/flood
Motorists should not attempt to drive around barricades or drive cars through flooded areas. Caution is urged when walking near riverbanks. Additional information is available at www.weather.gov. The next statement will be issued this evening at 700 PM CDT.
Flood Warning issued May 3 at 4:26AM CDT until May 6 at 1:00PM CDT by NWS Milwaukee/Sullivan WI
Effective: Sun May 3, 2026, 4:26 AM
Expires: Sun May 3, 2026, 4:30 PM
...The Flood Warning continues for the following rivers in Wisconsin...Illinois... Rock River Near Lake Koshkonong affecting Rock and Jefferson Counties. Rock River At Fort Atkinson affecting Jefferson County. Rock River At Afton affecting Winnebago and Rock Counties. ROCK RIVER near LEBANON-3 E-HWY MM BRIDGE affecting Dodge County. ...The Flood Warning is cancelled for the following rivers in Wisconsin... Rock River At Newville affecting Rock County. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Rock River near Lake Koshkonong. * WHEN...Until early Wednesday afternoon. * IMPACTS...At 10.5 feet, Floodwaters reach Oxbow Bend Road in the area of the gage on the east side of the lake. * ADDITIONAL DETAILS... - At 4:00 AM CDT Sunday the stage was 10.4 feet. - Bankfull stage is 9.0 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 4:00 AM CDT Sunday was 10.6 feet. - Forecast...The river is expected to fall below flood stage Wednesday morning and continue falling to 9.4 feet Saturday evening. - Flood stage is 10.0 feet. - Flood History...This crest compares to a previous crest of 10.5 feet on 08/30/2007. - http://www.weather.gov/safety/flood
Motorists should not attempt to drive around barricades or drive cars through flooded areas. Caution is urged when walking near riverbanks. Additional information is available at www.weather.gov. The next statement will be issued early this morning at 530 AM CDT.
Flood Warning issued May 3 at 10:59AM CDT until May 6 at 1:00AM CDT by NWS Milwaukee/Sullivan WI
Effective: Sun May 3, 2026, 10:59 AM
Expires: Sun May 3, 2026, 11:00 PM
...The Flood Warning continues for the following rivers in Wisconsin...Illinois... Rock River Near Lake Koshkonong affecting Jefferson and Rock Counties. Rock River At Afton affecting Rock and Winnebago Counties. Rock River At Fort Atkinson affecting Jefferson County. ROCK RIVER near LEBANON-3 E-HWY MM BRIDGE affecting Dodge County. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Rock River near Lake Koshkonong. * WHEN...Until early Wednesday morning. * IMPACTS...At 10.5 feet, Floodwaters reach Oxbow Bend Road in the area of the gage on the east side of the lake. * ADDITIONAL DETAILS... - At 10:00 AM CDT Sunday the stage was 10.3 feet. - Bankfull stage is 9.0 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 10:00 AM CDT Sunday was 10.6 feet. - Forecast...The river is expected to rise to a crest of 10.3 feet this afternoon. It will then fall below flood stage Tuesday evening. - Flood stage is 10.0 feet. - Flood History...This crest compares to a previous crest of 10.5 feet on 08/30/2007. - http://www.weather.gov/safety/flood
Motorists should not attempt to drive around barricades or drive cars through flooded areas. Caution is urged when walking near riverbanks. Additional information is available at www.weather.gov. The next statement will be issued this evening at 700 PM CDT.
Flood Warning issued May 2 at 7:00PM CDT until May 5 at 4:00AM CDT by NWS Chicago IL
Effective: Sat May 2, 2026, 7:00 PM
Expires: Sun May 3, 2026, 1:00 PM
...The Flood Warning continues for the following rivers in Illinois... Fox River at Algonquin Lock & Dam tailwater affecting McHenry, Kane and Lake IL Counties. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Fox River from Johnsburg downstream to Red Gate Road in St. Charles, including the Algonquin Lock & Dam tailwater gauge. * WHEN...Until Tuesday morning. * IMPACTS...At 10.5 feet, Structures threatened along Fox River Drive in East Dundee. Parking lots threatened in downtown West Dundee. Low-lying sections of Cornish Park are inundated in Algonquin. Low-lying sections of Trout Park inundated north of Elgin. * ADDITIONAL DETAILS... - At 6:30 PM CDT Saturday the stage was 10.4 feet. - Forecast...The river is expected to continue a gradual fall. - Flood stage is 9.5 feet. - http://www.weather.gov/safety/flood
A Flood Warning means water levels above flood stage are imminent or may already be occurring. Persons along rivers and streams in the warned area should take immediate precautions to protect life and property. These forecasts are based on observed precipitation as well as forecast precipitation 24 hours into the future. Changes to the rainfall forecast, or any additional rainfall after 24 hours, may cause changes to these river forecasts. Additional information is available at www.weather.gov. The next statement will be issued by Sunday afternoon.
Weather Forecast
Air Quality
Nitrogen Dioxide: 4.82 μg/m3
Sulphur Dioxide: 1.28 μg/m3
Ozone: 83.32 μg/m3
Astronomical
Sun Transit: 12:53 AM
Sunset: 7:59 PM
Daylight: 14 hrs 9 mins
Moon Transit: 2:00 AM
Moonset: 6:25 AM
Moon Phase: Full
Moon Illumination: 94.4%
Best Times for Fishing or Hunting
Major Periods
1:30 AM - 4:00 AM2:00 PM - 4:30 PM
Minor Periods
10:02 PM - 11:32 PM5:55 AM - 7:25 AM
Action Rating: 4 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 7.8 μg/m3
Sulphur Dioxide: 1.4 μg/m3
Ozone: 75.4 μg/m3
Astronomical
Sun Transit: 12:53 AM
Sunset: 8:00 PM
Daylight: 14 hrs 11 mins
Moon Transit: 2:49 AM
Moonset: 7:05 AM
Moon Phase: Waning Gibbous
Moon Illumination: 88.0%
Best Times for Fishing or Hunting
Major Periods
2:19 AM - 4:49 AM2:51 PM - 5:21 PM
Minor Periods
12:00 AM - 12:00 AM6:35 AM - 8:05 AM
Action Rating: 2 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 6 μg/m3
Sulphur Dioxide: 1.59 μg/m3
Ozone: 73.56 μg/m3
Astronomical
Sun Transit: 12:53 AM
Sunset: 8:01 PM
Daylight: 14 hrs 13 mins
Moon Transit: 3:40 AM
Moonset: 7:53 AM
Moon Phase: Waning Gibbous
Moon Illumination: 79.8%
Best Times for Fishing or Hunting
Major Periods
3:10 AM - 5:40 AM3:42 PM - 6:12 PM
Minor Periods
7:23 AM - 8:53 AM12:00 AM - 12:00 AM
Action Rating: 3 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 4.47 μg/m3
Sulphur Dioxide: 1.29 μg/m3
Ozone: 70.24 μg/m3
Astronomical
Sun Transit: 12:53 AM
Sunset: 8:02 PM
Daylight: 14 hrs 16 mins
Moon Transit: 4:32 AM
Moonset: 8:49 AM
Moon Phase: Waning Gibbous
Moon Illumination: 70.0%
Best Times for Fishing or Hunting
Major Periods
4:02 AM - 6:32 AM4:33 PM - 7:03 PM
Minor Periods
8:19 AM - 9:49 AM12:00 AM - 12:00 AM
Action Rating: 2 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 5.5 μg/m3
Sulphur Dioxide: 1.09 μg/m3
Ozone: 53.85 μg/m3
Astronomical
Sun Transit: 12:53 AM
Sunset: 8:03 PM
Daylight: 14 hrs 18 mins
Moon Transit: 5:22 AM
Moonset: 9:50 AM
Moon Phase: Waning Gibbous
Moon Illumination: 59.1%
Best Times for Fishing or Hunting
Major Periods
4:52 AM - 7:22 AM5:23 PM - 7:53 PM
Minor Periods
9:20 AM - 10:50 AM12:30 AM - 2:00 AM
Action Rating: 3 out of 5