But there's also been massive flooding in the Southwest, wildfires in the Northwest, extreme heat and humidity in the Northeast, and three powerful hurricanes.
The lack of water is hitting the Midwest corn crop especially hard and, as Cynthia Bowers
The drought has left the river within two feet of it's all-time low.
Engineers have been dredging for weeks to keep St. Louis' harbor open, and barge operators have been lightening their loads to keep from running aground.
"We keep getting calls from the industry to different boats going up and down the river, telling us where they've rubbed or where they hit some shallow water," says dredge captain Terry Bequett.
It's particularly bad, says Bowers, in Cairo, Ill., near where the Ohio and Mississippi Rivers converge. Barges are stacked up, taking turns going through the now narrow channel.
A summer of endless sunshine has also dried up any hopes for the corn crop in Illinois and Missouri.
Showing Bowers a shriveled-up, crackling ear of corn, Missouri farmer Mike Henry says the corn is in such bad shape "strictly" from a lack of moisture.
By this time of year, Bowers notes, the corn stalks should be towering tall enough for a farmer to get lost in, but they're less than half that size.