Imports into the United States from China increased over the past three months, despite challenges, including strikes by US dockworkers that threatened to slow down the supply chain.

The number of import containers arriving at US ports was elevated for July, August and September, a report by logistics metrics firm Descartes shows.

Jackson Wood, director of industry strategy at Descartes, said in a statement: "Imports from China are contributing to overall US volumes, posting the three highest monthly volumes on record in July, August and September."

Overall, container-import volumes into the US in September exceeded 2.5 million twenty-foot equivalent units, or TEUs, the second time this year that volumes have reached that level and the third month in a row that they surpassed the threshold of 2.4 million TEUs, which has historically strained maritime logistics.

At least 1 million TEUs into the US came from China alone in July, more than 975,000 in August and over 989,000 in September, Descartes found.

In August, imports from China to the US mostly comprised consumer goods such as furniture, toys, games, sports equipment and bedding.

Peak season

Jonathan Gold, the vice-president of supply chain and customs policy at the National Retail Federation, or NRF, told China Daily: "The current cargo volume increases are due to the peak shipping season and retailers planning ahead for the winter holidays."

Gold explained that since the spring and summer, several uncertainties, including the threat of major strikes on the East Coast and increased tariffs, had led retailers to "lengthen the peak shipping season" and bring in cargo earlier to ensure there were no issues due to snarled sea traffic.

The rise in cargo into US ports could signal that US consumers are readily spending ahead of the Thanksgiving and Christmas holidays. Many of the goods are made in China and sold by US retailers.

But Ben Hackett, founder of Hackett Associates, which produces NRF's Port Tracker and forecasts for US ports, said in a statement: "The surge in imports over the past few months has clearly been the result of contingency imports by wholesalers, retailers and industrial companies in anticipation of the East and Gulf Coast port strike rather than a sudden increase in demand."

It has been a tumultuous year for US ports after members of the International Longshoremen's Association, or ILA, went on strike at East and Gulf Coast container ports on Oct 1.

The job action came after the ILA's contract with employer group the US Maritime Alliance expired and negotiations between the two sides failed to reach an agreement on better wages and automation. The strike affected 36 ports, including major hubs such as New York and Houston, Texas. But the strike lasted only three days.

On Oct 3, the two sides reached a tentative agreement that suspended the potentially crippling strike. They extended their master contract until Jan 15, 2025, and will return to negotiate any outstanding issues.

More than 50,000 port workers participated in the strike, which was the biggest halt of work in the industry since 1977. It caused a backlog of anchored ships outside major ports and blocked the ability of ports from Maine to Texas to unload container ships.

Other recent obstacles on shipping routes include a drought in Central America, which made water levels fall in the Panama Canal, affecting the number of ships that could use that route.