Dense Fog Advisories in Iowa, 2021

Dense Fog Advisories by county

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

Over time

By month

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
Jan 1, 5:56 PM CST	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	21 hr
Jan 1, 10:00 PM CST	Dense Fog Advisory	DMX	Calhoun, Cerro Gordo, Emmet, Franklin, Hamilton, Hancock and 10 more	14 hr
Jan 2, 8:28 AM CST	Dense Fog Advisory	OAX	Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more	5 hr
Jan 2, 1:55 PM CST	Dense Fog Advisory	ARX	Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more	22 hr
Jan 2, 2:12 PM CST	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 45 more	22 hr
Jan 2, 2:49 PM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	21 hr
Jan 2, 2:53 PM CST	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	39 hr
Jan 2, 3:40 PM CST	Dense Fog Advisory	OAX	Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more	19 hr
Jan 3, 2:22 PM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	28 hr
Jan 3, 2:38 PM CST	Dense Fog Advisory	OAX	Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more	21 hr
Jan 3, 2:40 PM CST	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 45 more	21 hr
Jan 3, 2:58 PM CST	Dense Fog Advisory	ARX	Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more	24 hr
Jan 5, 2:02 PM CST	Dense Fog Advisory	ARX	Allamakee, Clayton	19 hr
Jan 5, 3:41 PM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	18 hr
Jan 6, 2:02 PM CST	Dense Fog Advisory	ARX	Clayton	19 hr
Jan 6, 2:37 PM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	13 hr
Jan 7, 2:42 PM CST	Dense Fog Advisory	FSD	Buena Vista, Clay, Dickinson, Lyon, O'Brien, Osceola and 1 more	20 hr
Jan 8, 2:30 PM CST	Dense Fog Advisory	FSD	Cherokee, Clay, Dickinson, Lyon, O'Brien, Osceola and 1 more	22 hr
Jan 31, 9:34 PM CST	Dense Fog Advisory	OAX	Fremont, Harrison, Mills, Monona, Montgomery, Pottawattamie and 1 more	38 hr
Feb 1, 11:39 PM CST	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	11 hr
Feb 2, 1:36 AM CST	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Audubon, Boone, Butler and 32 more	9 hr
Feb 2, 8:51 PM CST	Dense Fog Advisory	DMX	Adair, Appanoose, Black Hawk, Boone, Bremer, Butler and 37 more	12 hr
Feb 3, 1:04 AM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	10 hr
Feb 19, 10:01 PM CST	Dense Fog Advisory	OAX	Harrison, Mills, Monona, Pottawattamie, Shelby	14 hr
Feb 21, 8:24 PM CST	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 4 more	7 hr
Feb 22, 12:47 AM CST	Dense Fog Advisory	DMX	Audubon, Calhoun, Carroll, Cass, Crawford, Emmet and 11 more	5 hr
Feb 25, 10:11 PM CST	Dense Fog Advisory	ARX	Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more	9 hr
Feb 26, 1:09 AM CST	Dense Fog Advisory	DMX	Black Hawk, Bremer, Butler	4 hr
Feb 26, 1:19 AM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Delaware, Dubuque, Jackson, Jones and 1 more	4 hr
Feb 28, 6:13 AM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	6 hr
Feb 28, 6:49 AM CST	Dense Fog Advisory	ARX	Allamakee, Clayton, Fayette, Winneshiek	5 hr
Mar 16, 12:37 AM CDT	Dense Fog Advisory	DVN	Des Moines, Henry, Jefferson, Keokuk, Lee, Louisa and 2 more	9 hr
Mar 16, 12:52 AM CDT	Dense Fog Advisory	OAX	Fremont, Harrison, Mills, Montgomery, Page, Pottawattamie and 1 more	8 hr
Mar 16, 1:06 AM CDT	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Audubon, Boone, Calhoun and 25 more	8 hr
Mar 17, 12:39 AM CDT	Dense Fog Advisory	OAX	Mills, Pottawattamie	3 hr
Mar 17, 4:49 AM CDT	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Audubon, Boone, Calhoun and 21 more	4 hr
May 16, 3:13 AM CDT	Dense Fog Advisory	DMX	Appanoose, Boone, Cerro Gordo, Clarke, Dallas, Davis and 30 more	5 hr
May 19, 1:59 AM CDT	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	7 hr
May 19, 2:45 AM CDT	Dense Fog Advisory	OAX	Harrison, Monona, Shelby	5 hr
May 31, 2:46 AM CDT	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 4 more	6 hr
Jun 1, 1:15 AM CDT	Dense Fog Advisory	OAX	Fremont, Montgomery, Page	9 hr
Jun 1, 1:18 AM CDT	Dense Fog Advisory	DVN	Cedar, Des Moines, Henry, Iowa, Jefferson, Johnson and 7 more	8 hr
Jun 1, 1:27 AM CDT	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Cass, Clarke, Davis and 14 more	8 hr
Jun 30, 4:22 AM CDT	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Dubuque and 8 more	4 hr
Jun 30, 4:35 AM CDT	Dense Fog Advisory	ARX	Allamakee, Clayton, Fayette	3 hr
Jul 1, 4:24 AM CDT	Dense Fog Advisory	DVN	Clinton, Des Moines, Henry, Lee, Louisa, Muscatine and 1 more	4 hr
Jul 31, 1:02 AM CDT	Dense Fog Advisory	FSD	Clay, Dickinson, Lyon, O'Brien, Osceola, Plymouth and 1 more	8 hr
Oct 4, 8:27 AM CDT	Dense Fog Advisory	ARX	Mitchell	118 min
Oct 4, 2:37 PM CDT	Dense Fog Advisory	DMX	Cerro Gordo, Hancock, Kossuth, Winnebago, Worth	18 hr
Oct 4, 2:38 PM CDT	Dense Fog Advisory	ARX	Floyd, Mitchell	18 hr
Oct 8, 3:52 AM CDT	Dense Fog Advisory	DVN	Dubuque, Jackson	5 hr
Oct 8, 9:34 PM CDT	Dense Fog Advisory	ARX	Allamakee, Clayton, Howard, Winneshiek	12 hr
Oct 8, 9:43 PM CDT	Dense Fog Advisory	DVN	Cedar, Clinton, Delaware, Dubuque, Jackson, Jones and 2 more	10 hr
Nov 4, 4:23 AM CDT	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	10 hr
Nov 4, 9:24 PM CDT	Dense Fog Advisory	FSD	Lyon, Sioux	5 hr
Dec 15, 2:56 AM CST	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	6 hr
Dec 24, 4:01 AM CST	Dense Fog Advisory	OAX	Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more	7 hr
Dec 24, 4:05 AM CST	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 39 more	8 hr
Dec 24, 7:47 AM CST	Dense Fog Advisory	ARX	Chickasaw, Fayette, Floyd, Howard, Mitchell, Winneshiek	6 hr
Dec 25, 11:52 PM CST	Dense Fog Advisory	DVN	Des Moines, Lee	12 hr
Dec 30, 7:17 PM CST	Dense Fog Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	23 hr
Dec 30, 8:47 PM CST	Dense Fog Advisory	ARX	Chickasaw, Clayton, Fayette, Floyd, Howard, Mitchell and 1 more	14 hr
Dec 30, 9:07 PM CST	Dense Fog Advisory	DMX	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 43 more	21 hr
Dec 31, 3:30 AM CST	Dense Fog Advisory	OAX	Fremont, Harrison, Mills, Montgomery, Page, Pottawattamie and 1 more	9 hr
Dec 31, 7:41 AM CST	Dense Fog Advisory	FSD	Buena Vista, Ida	4 hr

By county

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

59 more counties

The busiest days

Days with the most alerts issued, by UTC date.

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.