Follow the Last Freeze and Beginning of the Growing Season Across the Central U.S.

The beginning of the growing season is arriving in the central United States for Spring 2016. Spring temperatures have been warm, especially the high temperatures. However, sub-freezing temperatures have occurred often enough that the growing season has not yet fully begun. As we move further into spring, more sites will see their last freeze. A late spring freeze can be particularly damaging if the growing season has begun and plants have emerged from the ground. The image below, updated daily, will keep track of both freezes (temperatures falling to 32 degrees or colder) and growing degree days (which is a measure of how far into the growing season the area has progressed). Filled circles indicate that those sites have not had a freeze in the last 14 or more days, which means that those locations would be vulnerable to a late freeze if the sites also have accumulated enough growing degree days for sensitive plants to emerge. White shading on the map indicates areas that have accumulated at least 150 growing degree days, enough for early plants to emerge.

Last freeze and accumulated growing degree days

Also, the map of the median (middle, or usual) last freeze date (32 degrees) is below:

Median (middle) date of last spring freeze

All images are courtesy of the Midwest Regional Climate Center. To see these images and others, visit the Midwest Regional Climate Center's Climate Watch and Frost/Freeze Vegetation Impact Program.