The price of wheat for March delivery fell 2 cents to $7.63 a bushel. The price of the grain has now fallen for three days.
Wheat is currently in its winter dormancy period, before it starts growing again in the spring.
"The amount of moisture becomes crucial as the wheat gets ready to break dormancy and really utilize a lot of moisture," said Mike Zuzolo, president of Global Commodities Analytics and Consulting in Lafayette, Indiana.
In other trading, corn also fell while soybeans rose.
Corn for March delivery dropped 1.75 cents a bushel, or 0.2 percent, to $7.3425 a bushel. Soybeans rose 14.50 cents, or 1 percent, to $14.8875 a bushel.
Metals were mixed. Gold, platinum and palladium rose while silver and copper fell.
Gold for April delivery gained $5.80, or 0.3 percent, to finish at $1,676.40. Platinum for April gained $10.40, or 0.6 percent, to $1,698.10 and March palladium rose $1.40, or 0.2 percent, to $757.80.
Silver for March delivery fell 24.2 cents, or 0.8 percent, to $31.7160 an ounce. March copper fell 1.6 cents to $3.7685 a pound.
In energy trading, oil fell below $97 a barrel Monday on signs that the U.S. and Iran may restart nuclear negotiations. Oil futures had been rising steadily from around $86 a barrel in mid-December as hopes rose for an improving world economy, climbing close to $100 at the end of January.
Benchmark oil for March delivery fell $1.60, or 1.6 percent, to $96.17.
In other energy trading, heating oil and wholesale gasoline also fell, while natural gas rose.
March heating oil declined a fraction of a cent, or 0.2 percent, to finish at $3.1540 a gallon, and wholesale gasoline for March delivery dropped 4.2 cents, or 1.4 percent, to end the day at $3.0115 a gallon.
Natural gas for March delivery rose 1.4 cents, or 0.4 percent, to end at $3.3150 per 1,000 cubic feet.