A Dense Fog Advisory has been issued until 9am Tuesday morning for the following counties, Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard, Mitchell, Winneshiek, Black Hawk, Boone, Bremer, Butler, Calhoun, Carroll, Cerro Gordo, Dallas, Emmet, Franklin, Greene, Grundy, Hamilton, Hancock, Hardin, Humboldt, Jasper, Kossuth, Marshall, Palo Alto, Pocahontas, Polk, Poweshiek, Sac, Story, Tama, Webster, Winnebago, Worth and Wright.

Also a Dense Fog Advisory has been issued until 6am Tuesday morning for the following counties, Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines, Dubuque, Henry, Iowa, Jackson, Jefferson, Johnson, Jones, Keokuk, Linn, Louisa, Muscatine, Scott and Washington.

Visibilities have already dropped below a quarter mile in many locations in the state and will drop to near zero during the overnight and early morning hours. Make sure to use low beams if you will be driving tonight.