Year-over-year cargo volume at the Port of Long Beach climbed in September, rising 14.7 percent over last year’s activity, according to figures released Monday.

With more than 587,000 containers moving through the port, September was the second-busiest month of the year, behind August’s 630,000 (16 percent greater than the year earlier), as retailers continued to import goods to prepare for the coming holiday season.

Imports through Long Beach were up 16.2 percent over last September, while year-over-year exports rose by 17.2 percent.

Empties, containers sent overseas to be filled with goods, were up 9.4 percent.

The port said for the three months ended Sept. 30, imports were up 16.1 percent over the year-ago period.