Global air cargo tonnage grew 9% year on year in September, with Asia and North America doing most of the heavy lifting, according to the latest figures from WorldACD.

The data provider's monthly assessment puts the transpacific and intra-Asia flows at the centre of the expansion. Asia-originated traffic, long the bellwether for the wider market, and the North American market — both as an origin and as a destination — accounted for the bulk of the tonnage gains recorded across WorldACD's coverage.

For shippers, the headline number matters because September is traditionally the opening act of the peak season. A 9% year-on-year uplift at that point in the calendar signals that demand entered the fourth quarter from an already elevated base, tightening the room for error on capacity planning.

What does 9% growth mean for capacity and rates?

Tonnage expansion of this magnitude has direct commercial consequences. When demand grows at near double-digit rates, the available bellyhold and freighter capacity on the affected lanes comes under strain faster than carriers can reposition aircraft.

For forwarders, the practical effect is earlier sell-outs on prime departures out of Asian gateways and a reduced ability to roll cargo to later flights. Shippers with fixed transit commitments — electronics, e-commerce, fashion and perishables among them — face higher risk of spot exposure if their contracted allotments are exceeded.

For carriers, the growth is revenue-positive but operationally demanding. Airlines with dedicated freighter fleets and strong Asian networks are best placed to capture the incremental volumes; those dependent on belly capacity tied to passenger schedules have less flexibility to add tonnage where the demand actually sits.

Why Asia and North America are driving the market

The geographic pattern in the WorldACD data is consistent with the structural story that has shaped air cargo since the pandemic: Asian production and e-commerce fulfilment generating dense outbound flows, with North America as the principal consuming market.

Asia's role as the demand engine reflects its concentration of high-value, time-sensitive manufacturing and the continued expansion of cross-border e-commerce out of the region. North America's contribution, meanwhile, underlines the strength of import demand as well as the region's own export and domestic air freight activity.

When these two regions grow simultaneously, the effect compounds across the network rather than staying contained within a single lane. Connecting traffic via Gulf and European hubs also benefits, as carriers balance flows across their systems.

How shippers and forwarders should respond

Several practical implications follow from the September numbers:

• Book early on Asian departures. A 9% growth market leaves little slack on peak-day flights out of major Asian origin points.
• Lock in allotments where possible. Fixed-capacity agreements protect against spot-rate spikes if the growth trend persists into the fourth quarter.
• Watch the transpacific carefully. With Asia and North America both expanding, that trade lane is where capacity pressure and rate movement will show up first.
• Diversify routing options. Secondary gateways and off-peak departures become viable alternatives when prime capacity tightens.

What comes next

The key question for the remainder of the year is whether the September growth rate holds. WorldACD's figures will show in the coming months whether the peak season sustains the momentum that Asia and North America built in September, or whether capacity additions catch up with demand and cool the rate environment. Carriers, forwarders and shippers alike will be watching the October and November data for that verdict.