If you’re thinking of planting trees or shrubs in your yard... the U.S. Department of Agriculture has guidelines for what to plant depending on where you live. It’s called the Plant Hardiness Zone Map. It’s based on average minimum winter temperatures. So you can use it to decide if the kind of tree you want to plant will make it through the winter without freezing to death.
This past January, the USDA updated this map for the first time since 1990.
But one researcher argues it’s already out of date.
Nir Krakauer is an assistant professor of civil engineering at the City College of New York. He says the USDA used the annual minimum temperatures between 1976 and 2005 to make their map. He updated that map with more recent data.
“In general, a lot of Michigan might be a half zone less cold than the USDA map would show.”