CHICAGO, April 19 (Reuters) - U.S. corn futures rose on Monday, flirting with multi-year highs set last week, as forecasts for frosty weather and precipitation raised concerns about the pace of planting and germination, analysts said.

A weaker dollar lent support, theoretically making U.S. grains more competitive globally.

Soybeans followed corn higher, but wheat was choppy, turning lower on profit-taking after reaching a six-week top.

Chicago Board of Trade May corn settled up 6-1/2 cents at $5.92 per bushel, hovering near last week's high of $6.01-1/2, the highest on a continuous chart of the most-active corn contract since June 2013.

CBOT December corn, representing the 2021 crop, set a life-of-contract high at $5.21-3/4 before finishing at $5.20-1/4.

CBOT May soybeans ended up 16-1/2 cents at $14.49-3/4 a bushel.

Corn rose as traders focused on U.S. crop weather, with sub-freezing temperatures expected across most of the Plains and the Midwest this week along with some snow and rain. Meanwhile, dry conditions persist in the northern Plains.

"There is enough concern in here, with Chinese (corn) imports being what they are, to keep the corn market fairly well bid right now," said Sterling Smith, director of agricultural research with crop insurer AgriSompo North America.

After the CBOT close, the U.S. Department of Agriculture said the U.S. corn crop was 8% planted, matching the five-year average but just behind the average estimate in a Reuters analyst poll for 9%.

The USDA said soybean planting was 3% complete, ahead of the five-year average of 2% and in line with trade expectations.

The USDA rated 53% of the U.S. winter wheat crop in good to excellent condition, unchanged from the previous week. Analysts on average had expected a decline of one percentage point.

CBOT May wheat settled down 1/4 cent at $6.52-1/4 a bushel, retreating after reaching $6.60-3/4, its highest since March 8.

But K.C. hard red winter wheat futures closed higher on worries about the Plains cold spell.

"Wheat prices are ... firmer on solid export shipments combined with increased weather risks," Arlan Suderman, chief commodities economist at StoneX, said in a client note. (Additional reporting by Michael Hogan in Hamburg Editing by Kirsten Donovan, David Goodman and David Gregorio)