Peak season: why imports surge August to October

Shipping peak season is the late-summer-into-fall stretch when US container imports run at their heaviest, historically August through October. The driver is the retail calendar. Goods sold in the fourth-quarter holiday rush have to be made, shipped, landed and trucked to shelves weeks ahead, so importers front-load the orders in the third quarter. That pull-forward is what turns the late-summer months into the busiest window on the import calendar.

Why the surge lands when it does

Work the holiday timeline backward. A product on a store shelf in November left an Asian factory two to eight weeks earlier depending on the route, and it was ordered weeks before that. To hit an October floor-set date a box generally has to ship by August, which is why import volume swells from midsummer. Back-to-school buying adds an earlier bump, and the two demand waves overlap into one long push through the third quarter. The boxes have to move before the quarter they serve, not during it.

The factory calendar on the other end

The origin calendar shapes the year too. Chinese factories close for the Lunar New Year in late winter, usually a stretch in February, and production slows for weeks around it. Importers who need goods in the first quarter often pull those orders forward ahead of the shutdown, creating a second, smaller rush before the holiday one. Between the pre-Lunar-New-Year push early in the year and the peak-season push in late summer, the import calendar has two humps, and the fall one is the big one.

Peak has been moving

One honest caveat. The classic August-to-October peak has drifted earlier in recent years as importers pull cargo forward to get ahead of labor uncertainty, tariff deadlines and the risk of congestion. Some years the heaviest months now land in early summer. The pattern is a tendency, not a fixed schedule, and the volume data is where you see which shape a given year took.

See it in the multi-year shape

The chart above is the Los Angeles monthly volume with its history behind it. Read across several years and the seasonal shape stands out, loaded imports building through late summer and easing after the fall. Line up this year against the same months last year and you can see whether peak is early, late or on time. Historically the ship queue and box dwell tightened in these same months, because the same volume that fills the import bars fills the terminals behind them.

The Dwell shows the seasonal pattern in the volume data, dated to the month. It does not forecast how big a given peak will be. For how to read a fresh monthly release, see reading the monthly TEU release.