Congestion is intensifying across major Asian container ports, with deteriorating schedule reliability and growing vessel queues raising the risk of prolonged disruption to global supply chains.

Sea-Intelligence data showed that all 14 of Asia’s busiest container gateways recorded lower schedule reliability in July. Typhoons compounded the pressure on terminal operations that were already operating under strain.

Shanghai was among the most severely affected hubs, with schedule reliability falling to 21%. Ningbo recorded reliability of 34.6%, while Singapore, the world’s largest transhipment hub, achieved 43.2%.

Yantian posted the steepest month-on-month decline, with reliability dropping 23.5 percentage points to 48.3%. Hong Kong’s performance fell by 20.4 percentage points, while Ningbo registered a 20.1-point decrease.

The simultaneous deterioration at several key hubs indicates that congestion is extending beyond isolated port bottlenecks. Sea-Intelligence reported that eight major trade lanes ending in Asia experienced an average schedule reliability decline of 7.5 percentage points during July. These routes represented 39% of all vessel arrivals included in the consultancy’s monthly measurement.

The disruption was also reflected in global performance. Worldwide schedule reliability declined by 6.1 percentage points to 56.4%, marking the largest monthly fall since January 2021. Vessels arriving late were delayed by an average of 6.06 days.

Capacity losses associated with congestion are becoming increasingly visible outside port limits. Linerlytica estimated that more than 4.3 million teu of containership capacity was waiting for berths worldwide last week. According to the estimate, that total exceeded the absolute peak recorded during the pandemic.

Drewry has also warned that average vessel waiting times have almost doubled compared with 2019 levels.

Using a separate measure of capacity absorbed by delays, Sea-Intelligence estimated that congestion is currently tying up 6.6% of the global containership fleet, equivalent to approximately 2.3 million teu.

The consultancy expects the congestion overhang to persist for several months. It estimates that conditions could take between four-and-a-half and six months to return to the lows recorded in June 2025, extending the potential effects on shipping schedules and supply chains into the final quarter.