CBOT July corn settled up 9 cents at $4.50 per bushel.
Technical buying helped support the gains after the contract dropped to its lowest price since June 13 earlier in the session, traders said.
On Monday, the contract reached $4.64-1/4, the highest for a spot and most active corn contract since June 2014.
Forecasts call for more rain in the Farm Belt over the next five days, after storms caused unprecedented planting delays this spring.
Recent gains in US corn prices have reduced export demand, with South American suppliers competing for sales on the global market, traders said.
Weekly export sales of US corn totaled 399,200 tonnes, near the low end of market forecasts for 300,000 tonnes to 900,000 tonnes, according to the US Department of Agriculture.