The National Weather Service has issued a Frost Advisory for a large portion of the state for the early morning hours, mainly 4-7am (3-8am across far western and SW Iowa). Counties in the advisory include, Pocahontas, Humboldt, Wright, Franklin, Butler, Bremer, Sac, Calhoun, Webster, Hamilton, Hardin, Grundy, Black Hawk, Crawford, Carroll, Greene, Boone, Story, Tama, Audubon, Guthrie, Dallas, Polk, Jasper, Poweshiek, Cass, Adair, Madison, Warren, Marion, Mahaska, Adams, Union, Clarke, Lucas, Monroe, Wapello, Taylor, Ringgold, Decatur, Wayne, Appanoose, Davis, Monona, Harrison, Shelby, Pottawattamie, Mills, Montgomery, Fremont, Page, Buchanan, Delaware, Dubuque, Benton, Linn, Jones, Jackson, Iowa Johnson, Cedar, Clinton, Muscatine, Scott, Keokuk, Washington, Louisa, Jefferson, Henry, Des Moines, Van Buren and Lee. Like last night, temperatures are expected to drop into the upper 20s and lower 30s across the state (Freeze conditions are possible north of US Hwy 20), frost is possible, especially in cooler valley locations. If you have sensitive plants, make sure you either cover them up or bring them inside. Temperatures will rebound above freezing by 8am.