The Consumer Price Index (CPI) rose 1.6% on a year-over-year basis in September, following a 1.4% gain in August. The all-items CPI excluding gasoline rose 1.1% year over year in September, matching the gain in both July and August.

Prices were up in six of the eight major CPI components in the 12 months to September, with the transportation and shelter indexes contributing the most to the year-over-year rise. The clothing and footwear index and the household operations, furnishings and equipment index both declined on a year-over-year basis.

Transportation costs rose 3.8% on a year-over-year basis in September, following a 2.8% increase in August. For a third consecutive month, gasoline prices were the largest contributor to the gain in transportation prices and also to their acceleration. The gasoline index rose 14.1% in the 12 months to September, largely due to supply disruptions caused by Hurricane Harvey. The purchase of passenger vehicles index accelerated 1.0% year over year in September, up from a 0.7% increase in August.