Garden Trivia Answer
Based on data from the Midwestern Regional Climate Center (MRCC) from 1981 to 2010, the earliest first frost date recorded in Iowa was September 13th recorded in several cities including Atlantic, Webster City, Waterloo, Mason City, Decorah, Estherville, and Spencer.
The latest first frost date recorded in Iowa was November 19th recorded in both Beaconsfield and Keokuk.