The increases were across the board, with most of the ports reporting double-digit growth in loaded imports and exports, according to statistics released Tuesday on the Pacific Maritime Association Web site.
The container volume in Southern California was up 14 percent over January 2010. Imports were also up 14 percent and exports were up 14 percent for the month.
Oakland's total container volume increased 10 percent in January, with imports up 15 percent and exports increasing 7 percent.
Portland started from a smaller base, but the Oregon port recorded especially large gains. Total container volume increased 26 percent, imports were up 46 percent and exports increased 10 percent over January 2010.
Seattle and Tacoma reported an increase in total container volume of 13 percent. Imports increased 11 percent and exports were up 15 percent.