The Northwest Seaport Alliance (Seattle + Tacoma) Weekly Volumes & Metrics Report 9/24/25
Overview
For the week ending September 12, numbers were up compared to the week before but down year over year for all categories.
Monthly numbers were also released last week, showing an overall decline YoY of 18.7% from August 2024. This drop continues to be in part likely due to tariff impacts, but also is still within the timeframe that saw increased cargo based on the disruptions at Canadian’s ports last year, leading to inflated metrics. The full breakdown of August numbers can be found here.
International imports were up 27.2% from the week before, but down 23% compared to the September 2024 weekly average. Truck transactions were up 22.2% compared the week before and down 23.6% compared to the September 2024 weekly average. Vessel lifts were up 11.4% and down 16.6% for those respective metrics.
You can find previous week’s report here. You can find the full vessel schedule, including the 4 week look ahead and breakdown by harbor, here.
Vessel Calls
Week Ending September 5 – 11 Voyages (1 Void, 2 Delayed Arrival)
Week Ending September 12 – 13 Voyages (2 Void)
Week Ending September 19 – 13 Voyages (1 Void, 2 Delay)
Week Ending September 26 – 13 Voyages (1 Void, 1 Delay)
Weekly International Import Containers
Week Ending September 12 – 13,046 containers imported
+1.4% vs 2025 YTD (12,860)
-4.0% vs 2024 Weekly Average (13,592)
-23.0% vs September 2024 Weekly Average (16,936)
Weekly Truck Transactions (Containers In/Out of Terminal via Truck)
Week Ending September 12 – 21,547 truck transactions
-10.5% vs 2025 YTD Average (23,774)
-23.6% vs September 2024 Weekly Average (28,215)
Weekly Vessel Lifts (Containers On/Off a Vessel)
*Includes Empty Container Moves
Week Ending September 12 – 24,409
-10.0% vs 2025 YTD Average (26,829)
-16.6% vs September 2024 Weekly Average (29,261)
Market Intel
September is typically supply chain peak season, as stores and BCO’s bring in holiday related merchandise. This makes lower September numbers notable, as it is usually the NWSA’s largest month and was our largest month in 2024.
Market intel suggests that while some cargo is not coming in, Peak Season mostly occurred outside its usual time frame this year, happening in July and earlier in the year, as shippers looked to advance cargo in the face of tariffs.
There is no expectation for a typical Peak Season this year, which usually lasts into October. The largest trend has been deviation from standard shipping trends, making it difficult to track overall volumes.
This also impacts exports, which were down 18.1% in August, as they rely on vessel and rail availability driven in part by imports.