Business activity in the United States cooled in September, according to new data from S&P Global. The Flash Composite PMI Output Index eased to 53.6 points in September, down from 54.6 points in August. The Services Business Activity Index dipped to 53.9 points from 54.5 points, with both indices at three-month lows. Meanwhile, the Manufacturing PMI slowed to 52 points in September from an over three-year high of 53 points in August. All three index readings remain above the expansion threshold of 50 points.

These indexes are surveys of whether business conditions are improving. Scores above 50 show growth, while readings below 50 indicate contraction. Because the surveys are released earlier than most official data, they provide one of the earliest indicators of economic momentum.

Chris Williamson, Chief Business Economist at S&P Global Market Intelligence, stated that “further robust growth of output in September rounds off the best quarter so far this year for US businesses.” He added that the index figures suggest “the economy expanding at a 2.2% annualised rate in the third quarter.”