Aug. 16 (Bloomberg) -- Cotton futures climbed to a five- month high as rain threatened to lower yields and crop quality in the U.S., the worldΆs largest exporter.

Parts of the Southeast, including Georgia, the second- largest U.S. grower, will have “very wet conditions” in the next 30 days that may hurt crops as some cotton bolls are starting to open, Joel Widenor, the director of agricultural services at Commodity Weather Group LLC in Bethesda, Maryland, said yesterday. Production in the U.S. may fall to a four-year low, the government said on Aug. 12.

“Any further deterioration of the U.S. crop could spark some panic among traders,” Peter Egli, the Chicago-based director of risk management at Plexus Cotton Ltd., said in a report.

Cotton for December delivery gained 1.7 percent to settle at 93.32 cents a pound at 2:30 p.m. on ICE Futures U.S. in New York. Earlier, the price reached 93.72 cents, the highest for a most-active contract since March 15. This week, the fiber jumped 4.9 percent, the most in two months.

In 2013, cotton has climbed 24 percent, the most among 24 raw materials in the Standard & PoorΆs GSCI Spot Index.