Across the Corn Belt, heat continues to expand eastward.  Later Wednesday, maximum temperatures should reach 100°F or higher in much of the western Corn Belt, extending as far north as South Dakota and southern Minnesota, and east into the mid-Mississippi Valley portions of the eastern Corn Belt.  The heat will hasten summer crop maturation, possibly at the expense of yield potential. 

On the Plains, a late-season heat wave continues, except near the Canadian border. 

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