CHICAGO, April 14 (Reuters) - U.S. wheat, corn and soybean futures rallied on Wednesday, supported by concerns that a cold snap in the U.S. Midwest and Plains could hamper crop development, traders said.

Chicago Board of Trade corn gained 2.8% to hit its highest since June 2013.

Wheat futures posted the biggest increases, with CBOT soft red winter wheat futures jumping 3.2%, while K.C. hard red winter wheat rising 3.4%.

"Cold surge next week poses spotty wheat damage risk in southern one-third of the U.S. Plains; possible burn back to emerged Midwest corn," Commodity Weather Group said in a note to clients.

The weather also could cause some growers to delay their planting of corn and soybeans as crops seeded in the cold temperature could struggle to emerge from soils.

"U.S. temperatures aren't quite fitting into the 'severe' category but the current cold snap is plenty of keep enthusiasm for early corn and soybean seeding low, with conditions looking dry but cold for the next seven to 10 days or more as well," Matt Zeller, director of market information at StoneX, said in a note to clients.

By 11:29 a.m. CDT (1629 GMT), Chicago Board of Trade May corn futures were up 16-1/4 cents at $5.96-1/4 a bushel and CBOT May soybeans were up 24-1/4 cents at $14.13-3/4 a bushel.

CBOT May wheat was 21-1/2 cents higher at $6.51-1/4 a bushel.

Experts are predicting a dry spell in coming weeks on the European continent. The water deficit is already in place in U.S. spring wheat areas in the north of the country, French consultancy Agritel said in a note.

"The weather in France remains closely monitored," Agritel said. "Weather forecasts for the coming weeks point to a risk of water deficit, which adds to the firmness of prices, including on the 2021 crop." (Additional reporting by Naveen Thukral in Singapore and Sybille de La Hamaide in Paris; Editing by Marguerita Choy)