Chicago Board of Trade corn futures rose nearly 4% on Monday as worries about crop weather in the Midwest and Europe spurred buying after a U.S. holiday weekend, traders said.
CBOT September corn (CU26) settled up 15-1/4 cents, or 3.6%, at $4.38-1/4 per bushel.
Benchmark December corn (CZ26) ended up 16-1/4 cents, or 3.7%, at $4.57-3/4 per bushel, after reaching $4.58-3/4, its highest level since June 4.
Forecasts called for warmer-than-normal temperatures across the U.S. midsection next week, fueling weather worries as the nation's corn crop begins its critical pollination stage.
Over the Independence Day weekend, heavy rains swamped fields in parts of Iowa, Illinois, Wisconsin and other areas, analysts noted.
Ahead of the U.S. Department of Agriculture's weekly crop progress report due later on Monday, analysts surveyed by Reuters on average expected the agency to leave its corn condition ratings unchanged at 67% good-to-excellent.
Meanwhile, ratings for France's maize crop hit their lowest level in 13 years after last week's record heat wave, official data showed on Friday.
The USDA reported export inspections of U.S. corn in the latest week at 1,641,777 metric tons, above a range of trade expectations for 1,300,000 to 1,600,000 tons.
In Brazil, farmers had harvested 26.5% of the country's second-crop corn, compared to 28.4% at the same time a year ago, consultancy Patria Agronegocios said on Friday.