WASHINGTON — U.S. manufacturing growth accelerated last month to the highest level since May despite global supply chain disruptions.

The Institute for Supply Management, a trade group of purchasing managers, said today that its index of manufacturing activity rose to a reading of 61.1 percent in September, 1.2 percentage points above the August level of 59.9 percent.

It was the best showing for manufacturing since a reading of 61.2 in May. Any reading above 50 indicates growth in the sector. September marked the 16th consecutive month manufacturing has grown after contracting in April 2020 when the coronavirus triggered a nationwide shutdown.

In recent months, the biggest swing factor for manufacturers has been problems on the supply side as rising cases of the delta variant globally crimp supply, such as the slowing production of computer chips in Asia, which have hit automakers and others hard.