Most Iowa counties are seeing a trend toward longer growing seasons with spring last freeze dates coming earlier and fall first freeze dates later than previous decades, according to data provided by the Midwestern Regional Climate Center (MRCC) at Purdue University.

In conjunction with the USDA’s Midwest Climate Hub, the MRCC last month unveiled an online freeze date tool that allows users to search regional and county-specific data on the climatology of freezing temperatures across the north central and northeastern United States.

The online tool can provide...