A Freeze Warning is in effect from 1:00 a.m. to 8:00 a.m. for Pottawattamie, Mills, Montgomery, Fremont and Page Counties.
A Frost Advisory is in effect from 1:00 a.m. to 8:00 a.m. for Cass, Adair, Adams, Union, Taylor and Ringgold Counties.
The National Weather Service says sub-freezing temperatures as low as 30 will result in frost formation. Frost could kill sensitive outdoor vegetation if left uncovered.