Sugar maples, elms and other trees are already donning their colorful autumnal foliage in northern Wisconsin and parts of Minnesota.
Botanists say nighttime temperatures dipping into the 40s have tricked the trees.
"When you get the cool night, the sugars get trapped in the leaves ... you get more red color," Michael Adams, a former University of Wisconsin botany professor, told the Milwaukee Journal-Sentinel.
August averaged 4 degrees below normal in Wisconsin, the National Weather Service said.
The summer is the wettest on record in North Texas. Heavy rains from Tropical Storm Gaston left Shockoe Bottom in Richmond, Va., under feet of water. More than 30.34 inches of rain has fallen in central Virginia since June, setting a record.
Gov. Mark Warner declared a state of emergency in Richmond Monday night.