However, soybeans were choppy, turning higher at times, on worries about forecasts for hot, dry weather in the US Midwest over the next week.
"Hot and dry weather is nice for a week or 10 days," said Dan Basse of AgResource Co. "The ideal situation is warm weather with frequent showers."
The US Department of Agriculture (USDA) weekly crop progress report comes out on Monday, and analysts are hoping for some improvements after last week's report showed little progress in harvested crops.
Chicago Board Of Trade September corn futures were down 1 cent at $4.37-3/4 a bushel, as of 11:42 a.m. CDT (1642 GMT.)
Traders had viewed warmer weather last week as beneficial in helping fields dry out and boost plant development.
But forecasts showing heat building further in the next two weeks, with limited rainfall, were causing concern that late-planted corn and soybeans may be stressed.
Ahead of the USDA crop progress report, analysts on average expected the government to report a slight improvement in weekly crop condition ratings for corn and soybeans.
The USDA last week rated 56pc of the corn crop as good to excellent, and just 54pc for soybeans.
Grain markets are also looking ahead to Thursday's monthly supply and demand forecasts from the USDA.
The USDA surprised the market with its June 28 acreage report in which it pegged corn plantings well above trade expectations and soybean acreage lower than anticipated.
"The USDA needs to tread lightly with this report or else they will have egg all over their face," said Roy Huckabay with Linn & Associates, a Chicago brokerage.
CBOT August soybean futures were up 2 cents, or 0.23pc, to $8.78 a bushel, after falling 1.6pc on Friday.
Wheat futures fell, halting a two-session climb, despite declining estimates for wheat production in Russia, the world's top exporter.
SovEcon and IKAR, the leading agriculture consultancies in Moscow, on Monday downgraded their forecast for Russia's 2019 wheat crop as they continued to assess the negative impact of June's hot, dry weather.
CBOT September wheat futures were down 3 cents to $5.12 a bushel.