A woven PP bag program ordered in mid-August can pay 900 dollars more per 40-foot container than the same order placed in early June, and the difference is timing, not the bag. Freight markets follow a predictable annual cycle: capacity tightens from August through October on Asia to North America and Europe lanes, carriers file general rate increases, and peak season surcharges stack on top of base rates. Importers who know the calendar book capacity before the window opens and hold landed cost flat across the year.

This guide maps the peak season calendar for bag shipments, the surcharges that arrive with it, and the booking windows that protect both price and delivery date.

Rate levels vary by carrier, lane and year; the windows and lead times below are working ranges from freight and production practice, and every program should be confirmed against current carrier quotes.

When peak season actually starts for bag imports

Two demand waves drive the calendar for bags. The first is retail back-to-school and holiday freight, which loads onto vessels from China in August and September so it clears West Coast ports before Black Friday; this is the classic August to October peak on transpacific lanes. The second is the Lunar New Year production rush: factories in China close for one to three weeks around the holiday, so buyers pull forward orders to ship in December and January, which keeps Asia outbound capacity tight into February. European lanes follow the same shape, with a September to November peak ahead of winter retail, plus a secondary window in May and June for summer-season goods. A bag program that ships year-round therefore sees its tightest capacity and highest rates in two windows: August to October and December to January. The container loading math behind seasonal orders is covered in our moving bags in a 40ft container guide.

The surcharges that stack on bag shipments

When capacity tightens, carriers file three charges on top of the base ocean rate. A general rate increase (GRI) is a blanket rate bump filed on a set date, usually the first of a month, and common from July through November. A peak season surcharge (PSS) is a per-container fee, commonly 200 to 1,000 dollars per 40-foot equivalent unit depending on lane and year, applied from August through October. Congestion and equipment charges appear when ports or chassis pools back up, and these are the least predictable of the three. The United States Federal Maritime Commission regulates carrier practices on these charges, including the detention and demurrage billing rules that importers can dispute when containers are delayed through no fault of their own; the commission publishes the relevant rules at fmc.gov. Freight rate analytics firms such as Sea-Intelligence also publish monthly schedule reliability data that shows exactly when the peak congestion builds; their public reports are at sea-intelligence.com.

Booking windows by lane

Book the container before the window, not inside it. In the off-peak months of March to June, carrier bookings for bags can be confirmed two to three weeks ahead of the planned sailing. In the August to October peak, the same booking needs four to six weeks, and carriers may roll confirmed bookings to the next sailing when space fills, which adds one to two weeks of transit delay on top of the normal schedule. Transit time itself stretches in peak season: a China to Los Angeles sailing that runs 18 to 22 days off-peak can run 25 to 35 days door to door in September and October once port congestion is included. For importers moving bags to the United States, the duty and HTS side of the landed cost is covered separately in our US import duties guide, and the domestic leg options are compared in our pallet versus parcel routing guide.

How importers lock capacity and hold the rate

Three practices flatten the peak season spike. First, annual contracts: a 12-month service contract with fixed monthly volume holds a base rate through the peak, and carriers honor it ahead of spot cargo when space is allocated. Second, forward booking: confirm the sailing slot four to six weeks out in the August to October window, and ask for the booking confirmation in writing including the rate validity date, because GRIs can land inside a booking window. Third, split shipments: spreading a 10-container program across September and October instead of one month avoids the single-week congestion spikes and keeps demurrage risk low. A program that orders bags in June for October arrival pays the off-peak rate and avoids the surcharge stack entirely, which is why the calendar is a pricing tool, not just a logistics one.

Frequently asked questions

Plan the calendar before the quote

Freight timing decides landed cost as surely as fabric weight does. Importers who treat the peak season calendar as a planning input, booking June for October arrival, contracting annual volume, and confirming slots in writing, hold rates within a few percent across the year. Those who order into the window pay the surcharge stack and carry the roll risk. Both programs receive the same bag; only the calendar differs. Bulk moving bag programs and woven PP lines are quoted with freight planning support across our moving bag range and woven PP range, including packing plans that fit the container before the booking is placed.