Chicago Board of Trade (CBOT) corn, wheat settled higher for their fifth successive trading days on Tuesday, while soybeans also extended a little gains.

The most active corn contract for July delivery was higher of 0.5 cents, or 0.12 percent, to close at 4.2775 dollars per bushel. July wheat delivery added 1.50 cents, or 0.30 percent, to settle at 5.09 dollars per bushel. July soybeans rose 3 cents, or 0.26 percent, to close at 11.4125 dollars per bushel.

Analysts said that corn and soybeans settled a little higher on Tuesday as traders remained worried about the forecasts for hot weather in the U.S. Midwest and Southern plain in the coming days.

The hot weather forecasts have heightened awareness to the expected La Nina event this summer, Farm Futures Daily reported Tuesday, adding that the previous La Nina events have been linked to droughts.

The U.S. Department of Agriculture (USDA) said Tuesday morning that private exporters reported export sales of 180,000 tons of soybeans for delivery to China during the 2016/2017 marketing year. Analysts noted that this data gave additional support to soybeans on Tuesday. USDA already announced Monday export sales of of 125,000 tons of soybeans to unknown destinations.

As for the wheat, some analysts said that fresh fund short covering prompted wheat higher on Tuesday. CBOT floor brokers reported that funds have bought some 7,000 contracts of wheat before midday, according to the report of AgResource, the Chicago-based agriculture consultancy.

Outside the market, the U.S. dollar dropped against most major currencies on Tuesday. In theory, a weaker dollar usually supports U.S. agricultural commodities higher as the weaker dollar make them cheaper in the international market.

USDA released its weekly crop progress report Monday after the market closed. In the report, corn planted till the week of June 5 was rated at 98 percent, 4 percent higher than previous week and also higher than previous 5-year average, while corn condition was rated 75 percent as good to excellent, higher than previous week and previous year.

As for the wheat, the winter wheat condition was rated by USDA at 62 percent as good to excellent, 1 percent lower than previous week but 19 percent higher than previous year; while 79 percent of spring wheat was rated as good to excellent condition, unchanged from previous week but much higher than previous year.

Soybeans planted was 83 percent, also higher than previous week and past 5-year average, while 72 percent of soybeans was rated as good to excellent, which was 3 percent higher than previous year.