Inflation Hit 3.7% in September 2026: How to Read a CPI Report

Last checked: Nov 2, 2026

"Inflation" is one of those words that shows up in almost every market headline. Once a month, the U.S. government publishes the main report that measures it: the Consumer Price Index, or CPI. The latest one, covering September 2026, was released on October 14. Let's use it to learn how to read a CPI report.

What the September 2026 report said

According to the U.S. Bureau of Labor Statistics (BLS):

• The CPI rose 0.6% in September on a seasonally adjusted basis, after rising 0.4% in August.
• Over the last 12 months, prices rose 3.7%, up from 3.4% for the 12 months ending in August.
• Core CPI, which leaves out food and energy, rose 0.3% for the month and 2.6% over the year (up from 2.4% in August).
• Gasoline rose 9.1% in September, which the BLS said accounted for over half of the monthly increase. Over 12 months, gasoline was up 34.2% and the energy index was up 20.4%.
• Shelter rose 0.4% for the month.
• Food was unchanged for the month and up 2.5% over the year.

CNBC reported that economists surveyed by Dow Jones had expected monthly and annual gains of 0.6% and 3.6%, so the annual figure came in slightly above expectations. CNBC also linked the jump in energy costs to the ongoing U.S.–Iran conflict.

What is the CPI?

The CPI tracks the average change over time in prices people pay for a "basket" of goods and services: things like food, rent, gas, clothing, medical care and transportation. When the CPI rises, it means that basket costs more than it used to. That's inflation.

Headline vs. core: why there are two numbers

• Headline CPI includes everything in the basket.
• Core CPI removes food and energy.

Why remove them? Food and energy prices can swing a lot from month to month for reasons like weather or global conflicts. Core CPI is meant to give a clearer view of the underlying trend.

September 2026 is a textbook example: headline inflation (3.7%) was well above core (2.6%), largely because of energy. When those two numbers are far apart, it tells you where the pressure is coming from.

Month-over-month vs. year-over-year

A CPI report gives both:

• Month-over-month shows how prices changed since last month. It's timely but can be noisy.
• Year-over-year shows how prices changed over 12 months. It's smoother and is the number most headlines use.

Reading both helps you see whether inflation is speeding up or slowing down.

Why investors care about inflation

1. Interest rates. The Federal Reserve's goal is 2% inflation. When inflation runs above that, the Fed is more likely to keep rates higher. (The Fed held rates steady at its Oct. 28 meeting and said inflation "remains elevated.")
2. Company costs and profits. Rising costs for fuel, materials and wages can squeeze profit margins, depending on whether companies can raise their own prices.
3. Your purchasing power. Inflation shrinks what cash can buy over time. That's a core reason many people learn about investing in the first place.
4. Market reactions. A CPI number that's hotter or cooler than expected can move stock and bond prices on release day.

When is the next CPI report?

According to the BLS release schedule, the CPI for October 2026 is scheduled for Tuesday, Nov. 10, 2026, at 8:30 a.m. ET. A great learning exercise: before it comes out, write down what last month's numbers were. Then compare when the new report arrives. You'll start to understand why markets react to surprises rather than the numbers themselves.

Key takeaways

• September 2026 CPI: up 0.6% for the month and 3.7% over 12 months (BLS).
• Core CPI rose 2.6% over the year; energy, especially gasoline, drove the headline number.
• Headline includes everything; core excludes food and energy.
• Inflation matters to investors through interest rates, company profits and purchasing power.
• The next CPI report is scheduled for Nov. 10, 2026.

Sources

• U.S. Bureau of Labor Statistics, "Consumer Price Index Summary – September 2026": https://www.bls.gov/news.release/cpi.nr0.htm
• U.S. Bureau of Labor Statistics, CPI release schedule: https://www.bls.gov/schedule/news_release/cpi.htm
• CNBC, "Consumer prices rose 3.7% annually in September as gas prices skyrocket," Oct. 14, 2026: https://www.cnbc.com/2026/10/14/cpi-inflation-report-september-2026.html
• Federal Reserve, FOMC statement, Oct. 28, 2026: https://www.federalreserve.gov/newsevents/pressreleases/monetary20261028a.htm