The Chicago Purchasing Managers' Business Barometer surged to 64.3 in August from 52.6 in July, the National Association of Purchasing Management-Chicago said Friday.
The data is compiled on a seasonally adjusted basis. An index reading below 50 signals a slowing economy, while a level above 50 suggests expansion.
Economists polled by Thomson Reuters predicted a 56.0 reading for the index.
"Strong growth in the Barometer and three of its key components in August followed a sharp slowdown in July. As expected, it appears that the July lull was temporary and that the momentum exhibited in the Chicago Report in the second quarter has carried through to Q3," according to the release.
