CHICAGO, July 28 (UPI) -- Grain futures surged higher on the Chicago Board of Trade Wednesday despite continued signs of beneficial weather in most growing areas.

Corn was up 12 3/4 to up 13 3/4, soybeans were up 12 to up 12 1/2, wheat was up 15 3/4 to up 20 1/2 and oats were up 10 1/2 to up 11 1/4.

Corn prices gained with the dollar index down slightly, off 0.08 percent, and reports of a mildly distressing heat spell expected in the Southwest. Wheat futures rose on a U.S. Department of Agriculture report that said Russian exports were down by 2.5 million metric tons in July compared to a year ago. Soybeans futures rallied with China purchasing 120,000 metric tons.

The prices:

Corn: Sep 3.76 1/4, up 13 1/2; Dec 3.90 3/4, up 13 3/4; Mar 4.03 1/2, up 13; May 4.11 1/3, up 12 3/4.

Soybeans: Aug 10.10, up 12 1/2; Sep 9.85, up 12; Nov 9.78, up 12 1/2; Jan 9.86 3/4, up 12 1/4.

Wheat: Sep 6.15 1/2, up 20 1/2; Dec 6.47, up 20; Mar 6.70 3/4, up 17 1/4; May 6.76 1/2, up 15 3/4.

Oats: Sep 2.57, up 10 1/2; Dec 2.69 1/4, up 11 1/4; Mar 2.76 1/4, up 11 1/4; May 2.83 1/4, up 11 1/4.