Here's the inflation breakdown for September 2026 — in one chart

Published: October 14, 2026

Key Points

• The consumer price index increased by 3.7% in September on an annual basis, as reported by the Bureau of Labor Statistics, up from 3.4% in August.
• The surge in inflation is primarily attributed to the ongoing Iran war, which has led to increased prices for oil and fuel products such as gasoline, diesel, and jet fuel.
• Additional factors influencing rising prices include tariffs, the development of artificial intelligence data centers, and sustained consumer demand in sectors like travel, according to economists.

Overview

In September, the inflation rate rose due to escalating gasoline and energy costs associated with the Iran war, further straining household budgets and potentially prompting the Federal Reserve to consider interest rate hikes, as noted by economists.

The Bureau of Labor Statistics reported that the consumer price index rose by 3.7% compared to one year ago, an uptick from the 3.4% annual rate recorded in August.

Economists focus on the "core" CPI, which excludes food and energy prices that tend to fluctuate and provides insight into the underlying inflation trends in the U.S. economy. This measurement saw an increase to 2.6% in September, up from 2.4% in August.

"The overall report indicates that inflation remains uncomfortably strong," remarked Mark Zandi, chief economist at Moody's.

He further emphasized, "The impact of the war is evident throughout the report, driving much of the inflationary spike."

'Frustration' over cost of living

This inflation reading arises less than a month before the midterm elections, where affordability is considered a critical concern among voters.

With rising prices for various goods and services, Treasury bond yields have surged in recent months, creating upward pressure on mortgage rates, auto loans, and other forms of consumer credit.

The Federal Reserve, the central bank of the U.S., which employs interest rate policy to regulate inflation, may opt to raise its benchmark interest rate in future policy meetings to combat persistently high inflation, as per economists' analysis. Changes to this benchmark rate have a direct impact on credit card interest rates and affect other borrowing costs as well.

The Federal Reserve aims for an annual inflation target of approximately 2%, a mark that inflation has exceeded for more than five years.

Zandi indicated that Wednesday's CPI report further supports the notion that the Federal Reserve will continue to escalate rates.

According to an analysis by Wells Fargo Investment Institute, inflationary pressures are expected to compel the Federal Reserve to raise rates between now and spring 2027.

Consumer sentiment metrics have declined to multi-year lows amidst rising prices. The University of Michigan's consumer sentiment index dropped to its second-lowest recorded reading in September.

Joanne Hsu, Director of the University of Michigan Surveys of Consumers, remarked, "Frustration over the cost of living is increasing. Consumers across the political spectrum feel that the state of the economy has weakened since the start of the year."

On Wednesday, the Social Security Administration announced a cost-of-living adjustment of 3.6% for benefits in 2027, calculated based on the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W).

However, a recent survey by AARP revealed that 76% of respondents believe a 3.5% COLA is insufficient.

Impact of the Iran war, oil prices on inflation

The Iran war, which commenced at the end of February when the U.S. and Israel attacked Iran, has significantly elevated oil prices.

This escalation has also resulted in rising costs for fuels such as gasoline, diesel, and jet fuel—products derived from crude oil—thereby affecting the broader economy, according to economists.

Michael Reid, head of U.S. economics at the Royal Bank of Canada, stated, "The inflation narrative is largely driven by oil. This trend is likely to continue for a few more months."

The conflict has substantially hindered oil transit through the Strait of Hormuz, a vital channel in the Middle East responsible for a large portion of global oil transport. This situation has compromised regional refining capabilities and limited supplies of other essential commodities, including fertilizers, thereby exerting upward pressure on global food prices.

Further complicating the situation, the ongoing war in Ukraine has also driven up diesel prices, largely due to damage inflicted on Russian refineries by Ukrainian assaults, as observed by economists.

Despite crude oil still passing through the Strait of Hormuz, it remains below pre-war levels. Even with significant waterways reopening, lingering challenges related to lost refining capacity and distribution issues may keep energy prices elevated until mid-2027, according to the analysis by Wells Fargo Investment Institute.

Gasoline prices soared by 9.1% in September alone, contributing to more than half of the monthly increase in the consumer price index, as indicated by the Bureau of Labor Statistics. Overall, gas prices have increased by 34% year-on-year.

As of Wednesday, the average national gas price reached $4.33 per gallon, marking a 45% hike from $2.98 per gallon on February 27, just before the onset of the Iran war, according to data from AAA.

While the surge in gasoline costs has created challenges for drivers, the impact of heightened diesel prices is felt more broadly across consumers.

Diesel, a crucial fuel for trucks, trains, and ships responsible for transporting goods, also serves various purposes beyond logistics, including in agriculture, manufacturing, and residential heating.

The average price of diesel stood at $6.30 per gallon on Wednesday, up approximately 68% from $3.76 per gallon before the Iran conflict, according to AAA.

Reid commented, "Someone has to absorb those costs."

However, the transmission of higher fuel prices to consumers is not instantaneous; there is typically a lag of a few months in this process.

As the holiday shopping season approaches, a time when retailers traditionally offer attractive discounts, Reid noted that he will be monitoring whether businesses opt for fewer or smaller discounts than usual.

According to CPI data, airline fare prices have risen by 22% over the past year, primarily reflecting elevated jet fuel prices, as noted by economists.

Additionally, robust consumer demand has also fueled increased travel costs, as evidenced by hotel and motel prices rising over 4% in the past year according to CPI figures.

Zandi remarked, "A significant portion of this demand can be attributed to high-income travelers. Wealthy Americans are traveling more as their stock portfolios and net worth have appreciated, driving considerable spending."

Other sources of inflation

The inflationary pressures from the Iran war and energy prices are not the sole contributors, as identified by economists.

"It's the combination of tariffs on top of everything else, complicating the already high energy prices," Reid explained.

Research from RBC Economics suggests that the interplay of tariffs and transportation costs is becoming evident in the prices of recreational goods.

Notably, toys and other recreational products—predominantly imported—recorded their most significant monthly price fluctuations, as detailed in the September CPI report.

Furthermore, the rapid construction of data centers driven by artificial intelligence has increased demand for, and consequently, the scarcity of, the computer chips necessary for these facilities. These chips are integral to various consumer electronics, including laptops, gaming consoles, and automobiles.

For instance, Apple has already announced price hikes for MacBooks and iPads due to soaring memory and storage costs. Microsoft followed suit with plans to increase Xbox console prices for similar reasons.

A positive note in the inflation report came from Zandi, who pointed out that grocery prices experienced a slight decline of 0.1% over the month, notwithstanding the increase in diesel costs.

Specifically, beef prices fell by 1% during the month, a decline that Zandi attributed at least in part to a temporary suspension of previously imposed tariffs on beef announced by President Donald Trump in August.