Consumer inflation continued its gradual climb in September, with the Consumer Price Index for All Urban Consumers (CPI-U) rising 0.3 percent on a seasonally adjusted basis for the month. Over the last 12 months, the all items index increased 3.0 percent, according to the U.S. Bureau of Labor Statistics (BLS).

The most notable contributor to the monthly rise was gasoline, which jumped 4.1 percent in September as energy prices broadly increased by 1.5 percent. Energy, which includes fuel oil, natural gas, and electricity, saw a 2.8 percent increase over the past year. Electricity prices rose sharply by 5.1 percent, while natural gas prices climbed 11.7 percent year-over-year. Despite the current monthly gains, gasoline remains 0.5 percent lower than its price level a year ago.​

Food costs also continued their upward trend, increasing by 0.2 percent in September and 3.1 percent over the last 12 months. Grocery store prices (food at home) rose 0.3 percent this month, with cereal and bakery products and nonalcoholic beverages leading the way, each up 0.7 percent. The ‘meats, poultry, fish, and eggs’ category rose 0.3 percent month-over-month and a notable 5.2 percent year-over-year. Eating outside the home (food away from home) saw a modest 0.1 percent monthly bump and 3.7 percent annual growth.

The index for all items less food and energy — often considered a measure of underlying or “core” inflation — increased 0.2 percent in September and is up 3.0 percent compared to September 2024. Shelter costs contributed to inflation, with a 0.2 percent monthly rise and a 3.6 percent increase year-over-year. Owners’ equivalent rent, a key measure of housing costs, posted its smallest one-month increase since January 2021, at just 0.1 percent.​

Other sectors registering increases in September include airline fares (up 2.7 percent for the month and 3.2 percent year-over-year), recreation (up 0.4 percent monthly, 3.0 percent annually), household furnishings and operations (up 0.4 percent monthly, 4.1 percent annually), and apparel (up 0.7 percent monthly, while down 0.1 percent for the year). Motor vehicle maintenance and repair maintained a brisk inflation rate, rising 7.7 percent over the past year. However, indexes for motor vehicle insurance, used cars and trucks, and communication posted declines for the month.

Inflation was relatively consistent across geographic regions. The Northeast, Midwest, South, and West saw annual CPI increases ranging from 2.7 percent to 3.5 percent. Major metropolitan areas such as Los Angeles, New York, Chicago, and Boston posted annual all-items inflation with figures between 2.9 percent and 3.9 percent. The West generally observed higher rates, and the lowest inflation was recorded in the South region’s largest cities at 2.3 percent.

The September CPI data was released before a lapse in federal appropriations.