Alert archive / Illinois / Dense Fog Advisories / 2021

Dense Fog Advisories in Illinois, December 2021

17 dense fog advisories in December 2021. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of dense fog advisories reaches back to 2005.

Dense Fog Advisories by county

Each county as a circle sized by its count in December 2021. Tap one for its archive.

Dense Fog Advisories: 17
Busiest day: December 26, 20214 dense fog advisories

Over time

By day

Days in UTC, the clock the archive keeps.

The alerts

Every alert, in the order issued. Times are local, Central Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Counties	Lasted
Dec 2, 2:00 AM CST	Dense Fog Advisory	PAH	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 11 more	4 hr
Dec 3, 10:49 PM CST	Dense Fog Advisory	LOT	Boone, DeKalb, Kane, Lake, Lee, McHenry and 2 more	3 hr
Dec 4, 6:13 AM CST	Dense Fog Advisory	LOT	Ford, Grundy, Iroquois, Kankakee, Kendall, LaSalle and 2 more	3 hr
Dec 10, 12:19 AM CST	Dense Fog Advisory	ILX	Cass, Champaign, Christian, Clark, Clay, Coles and 23 more	11 hr
Dec 10, 12:27 AM CST	Dense Fog Advisory	LOT	Ford, Grundy, Iroquois, Kankakee, Livingston, Will	12 hr
Dec 10, 2:28 AM CST	Dense Fog Advisory	LSX	Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 9 more	9 hr
Dec 25, 11:52 PM CST	Dense Fog Advisory	DVN	Bureau, Hancock, Henderson, Henry, McDonough, Putnam and 1 more	12 hr
Dec 25, 11:55 PM CST	Dense Fog Advisory	LSX	Adams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more	12 hr
Dec 25, 11:55 PM CST	Dense Fog Advisory	PAH	Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 10 more	10 hr
Dec 26, 1:13 AM CST	Dense Fog Advisory	ILX	Cass, Christian, DeWitt, Fulton, Knox, Logan and 13 more	11 hr
Dec 27, 8:11 AM CST	Dense Fog Advisory	LOT	Boone, Cook, DeKalb, DuPage, Ford, Grundy and 9 more	4 hr
Dec 29, 7:31 AM CST	Dense Fog Advisory	PAH	Alexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more	2 hr
Dec 29, 10:01 PM CST	Dense Fog Advisory	PAH	Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 11 more	11 hr
Dec 29, 10:09 PM CST	Dense Fog Advisory	LSX	Bond, Calhoun, Clinton, Fayette, Jersey, Madison and 5 more	14 hr
Dec 30, 7:17 PM CST	Dense Fog Advisory	DVN	Bureau, Carroll, Hancock, Henderson, Henry, Jo Daviess and 7 more	23 hr
Dec 30, 9:23 PM CST	Dense Fog Advisory	LSX	Adams, Bond, Brown, Calhoun, Clinton, Fayette and 8 more	15 hr
Dec 30, 9:28 PM CST	Dense Fog Advisory	ILX	Cass, Champaign, Christian, Clark, Clay, Coles and 29 more	13 hr

By county

Every county with at least one alert. A county page lists each alert that covered it.

62 more counties

Nearby

Alerts in force now Tornadoes on record The radar archive 2020 2022

Sources

National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.