WASHINGTON (AP) -- Food prices could rise next year because an unseasonably hot summer is expected to damage much of this year's corn crop.

The U.S. Department of Agriculture estimates a surplus of 672 million bushels of corn will be left over at the end of next summer. The estimated surplus is down from last month's forecast and well below levels that are considered healthy.

This spring, farmers planted the second-largest crop since World War II. But high temperatures stunted the plants.

Corn prices soared to record levels earlier this year because of limited supplies. More expensive corn drives food prices higher because corn is an ingredient in everything from animal feed to cereal to soft drinks. It takes about six months for corn prices to trickle down to products at the grocery store.