Dense Fog Advisories in Iowa
1,328 dense fog advisories since 1986. 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 since 1986. Tap one for its archive.
- Dense Fog Advisories
- 1,328
- Busiest year
- 2024110 dense fog advisories
- Average year
- 60over 22 years on file
Over time
By year
Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.
By month of the year
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Jones County221
- Dubuque County215
- Jackson County215
- Cedar County213
- Linn County212
- Clinton County211
- Muscatine County209
- Osceola County209
- Scott County207
- Johnson County202
- Benton County199
- Delaware County199
- O'Brien County199
- Washington County198
- Clarke County196
- Jasper County196
- Cerro Gordo County195
- Dickinson County195
- Hardin County195
- Louisa County195
- Lucas County195
- Des Moines County194
- Franklin County194
- Hancock County193
- Marion County193
- Story County193
- Grundy County192
- Henry County192
- Marshall County192
- Wright County192
- Buchanan County191
- Lyon County190
- Poweshiek County190
- Decatur County189
- Hamilton County188
- Sioux County188
- Tama County188
- Worth County187
- Black Hawk County186
- Iowa County186
59 more counties
- Wayne County186
- Keokuk County185
- Butler County184
- Clay County184
- Lee County184
- Winnebago County183
- Bremer County182
- Cherokee County182
- Jefferson County182
- Mahaska County182
- Boone County181
- Union County181
- Warren County181
- Monroe County180
- Buena Vista County178
- Floyd County178
- Howard County178
- Chickasaw County177
- Kossuth County176
- Greene County175
- Ringgold County175
- Webster County175
- Winneshiek County175
- Fayette County174
- Humboldt County174
- Mitchell County174
- Wapello County174
- Appanoose County172
- Madison County172
- Van Buren County168
- Montgomery County167
- Polk County167
- Plymouth County164
- Pottawattamie County164
- Adair County163
- Calhoun County162
- Clayton County162
- Dallas County162
- Davis County162
- Emmet County162
- Mills County162
- Adams County160
- Carroll County160
- Fremont County160
- Palo Alto County160
- Allamakee County159
- Page County159
- Taylor County159
- Guthrie County158
- Ida County157
- Pocahontas County157
- Cass County156
- Shelby County155
- Sac County151
- Harrison County150
- Audubon County148
- Woodbury County144
- Crawford County143
- Monona County136
The latest dense fog advisories
The most recent on file, newest first.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 30, 1:43 AM CDT | Dense Fog Advisory | FSD | Cherokee, Lyon, O'Brien, Osceola, Plymouth, Sioux and 1 more | 8 hr |
| Sep 17, 1:27 AM CDT | Dense Fog Advisory | FSD | Buena Vista, Cherokee, Ida | 10 hr |
| Sep 16, 10:57 PM CDT | Dense Fog Advisory | OAX | Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more | 11 hr |
| Sep 16, 9:26 PM CDT | Dense Fog Advisory | DVN | Benton, Buchanan, Delaware, Henry, Iowa, Jefferson and 6 more | 12 hr |
| Sep 16, 8:20 PM CDT | Dense Fog Advisory | DMX | Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 38 more | 14 hr |
| Sep 11, 2:07 AM CDT | Dense Fog Advisory | DVN | Cedar, Clinton, Des Moines, Dubuque, Henry, Jackson and 8 more | 8 hr |
| Sep 8, 11:39 PM CDT | Dense Fog Advisory | FSD | Buena Vista, Cherokee, Clay, Dickinson, Ida, O'Brien and 4 more | 8 hr |
| Sep 5, 4:46 AM CDT | Dense Fog Advisory | ARX | Chickasaw, Floyd, Howard, Mitchell | 4 hr |
| Sep 1, 3:57 AM CDT | Dense Fog Advisory | DMX | Black Hawk, Bremer, Butler, Grundy, Marshall, Tama | 4 hr |
| Sep 1, 1:42 AM CDT | Dense Fog Advisory | DVN | Benton, Buchanan, Delaware, Dubuque, Jones, Linn | 7 hr |
| Aug 26, 1:33 AM CDT | Dense Fog Advisory | OAX | Fremont, Mills, Montgomery, Page | 7 hr |
| Aug 20, 2:21 AM CDT | Dense Fog Advisory | FSD | Plymouth, Woodbury | 7 hr |
Nearby
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.