The National Weather Service has issued a frost advisory for the entire state of Iowa in effect from 4am to 7am Saturday. Temperatures will fall throughout the overnight hours, with the coldest temperatures occurring in the early morning hours near sunrise. Low temperatures will fall into the low to mid 30s. These temperatures will be approaching record low temperatures as shown in the image below.
Sensitive outdoor vegetation could be damaged or killed if left unprotected, specially in sheltered or low laying areas. This cold will be short lived as temperatures will warm up into the 60s and 70s this weekend, with a chance of thunderstorms returning next week.