"There were very good rains over the weekend and another round of showers are expected in the northwest Midwest today and tomorrow," said Don Keeney, a meteorologist for MDA EarthSat Weather.

Keeney said the central and eastern Midwest should receive from 0.30 inch to 1.00 inch Thursday and Friday, and high temperatures will be in the 80s (degrees Fahrenheit) rather than the 90s F.

"Temperatures will be cooler late this week, a high of only 77 F in Chicago by Friday but there's a return to heat next week," Keeney said.

Keeney said some of the late-planted U.S. soybean crop would benefit from the late summer turn to damper weather but the lion's share of the U.S. corn crop has already been affected by the worst drought in 56 years.

Corn and soybean prices were driven to record highs in late July as the drought worsened, trimming crop production. Prices for each eased on Monday but by Tuesday the market was turning higher again on concerns about more crop losses.

Relentless heat and drought has slashed prospects for the U.S. corn crop to a five-year low and the supply of corn next year is expected to fall to its lowest in nearly 20 years.

The U.S. Department of Agriculture (USDA) on Friday will release its August crop report and traders are bracing for the worst.

U.S. soybean inventories could fall to their lowest level in 32 years as the drought continues to trim U.S. soybean production prospects.

Soybean conditions began to stabilize last week on improved crop weather in a broad swath of the Midwest while corn conditions declined another one percentage point. However the ratings for each remained the worst since 1988 as the heat and dryness took a huge bite out of crop prospects.

Commodity Weather Group (CWG) on Tuesday said rains were still limited for the central and southwest Midwest and at least one-third of the Midwest soybean belt and over half of the Delta soybeans will remain under drought stress this week.