On March 31, 2026, the national average price of gas reached $4.02 a gallon, according to AAA, the first time above $4 since 2022, the year Russia's invasion of Ukraine sent prices soaring. AAA's figures put the national average at $2.98 on February 26, just before the U.S. and Israel began striking Iran on February 28, so the increase in just over a month was about 35%. By April 2, the most expensive state, California, was at $5.89.
The climb was steady: $3.25 on March 5, $3.94 on March 22 and $3.98 on March 26, before crossing $4 on March 31. AAA tied the rise to crude oil prices surging past $100 a barrel with the Strait of Hormuz closed. Brent crude had hit a high of $119 a barrel on March 19.
The damage extends beyond the pump. Diesel topped $5 a gallon on March 16 for the first time since December 2022, up by more than a third since the war began, according to AAA figures reported by Bloomberg. A University of Idaho economist said nitrogen fertilizer prices had risen as much as 40% at the farm gate. The OECD raised its forecast for 2026 U.S. inflation to 4.2%, 1.2 points higher than its December forecast, citing the war's energy shock along with a tight labor market and tariffs.
The war is also eating Trump's tax cut. The Associated Press reported that spiking gas prices were on track to consume the larger tax refunds from the One Big Beautiful Bill. Stanford economist Neale Mahoney calculated that in a scenario where gas peaked at $4.36 in May, the average household would pay $740 more for gas in 2026, nearly equal to the $748 increase in refunds the Tax Foundation estimated. Prices then went higher than that scenario: AAA put the national average at $4.55 on May 7.
On the day gas crossed $4, Trump told countries short of jet fuel because of the Strait of Hormuz closure, singling out the United Kingdom for refusing to join the war, to buy American fuel or “build up some delayed courage, go to the Strait, and just TAKE IT.”
Correction (October 14, 2026): This entry previously said Brent crude peaked at $126 a barrel; the Washington Examiner reported a high of $119 on March 19, and no source confirmed $126. Weekly prices of $3.48 (March 8), $3.72 (March 15) and $3.94 (March 21) have been replaced with figures from AAA and the Associated Press. California's $5.89 was AAA's April 2 figure, not March 31. The household cost was given as $740 to $857; the Associated Press reports a single Stanford estimate of $740 under a specific price scenario. Diesel was described as up 40% or more; Bloomberg reports more than a third. The tax-refund finding was attributed to CNBC; it comes from the Associated Press. Claims that 5 million Northeast heating-oil households saw bills double, that nitrogen fertilizer would double and phosphate rose about 50%, that the 30-year mortgage rate reached 6.53%, a Goldman Sachs inflation warning, and a consumer-sentiment low could not be confirmed and have been removed, as have statements about the war's congressional authorization and Biden's approval ratings that had no source. A May 3 national average of $4.39 from an unidentified NBC rundown has been replaced with AAA's May 7 figure. Spirit Airlines was described as the first major airline in 25 years to fold, with 17,000 jobs lost; Reuters called it the industry's first casualty linked to the Iran war, said the airline was already struggling before the fuel shock, and put the job losses at about 15,000.
Update (November 2, 2026): On the day before the midterms, AAA put the national average for regular gas at $4.1694, down from $4.2858 a week earlier and up from $3.0361 a year earlier. That is not a daily record: AAA's highest recorded average for regular remains $5.0165, on June 14, 2022. Diesel was $6.2921, below its record of $6.5276 on September 22, 2026.
A different measure did set a mark. A Financial Times analysis of federal data put average gas prices under Trump at $3.46 a gallon, surpassing the prior record set under Biden, according to the Daily Beast's summary; the tracker could read only the FT's headline, not its text. A White House official maintained that prices were higher under the previous administration when adjusted for inflation, the Beast reported, and spokesperson Taylor Rogers told the FT that confronting Iran “was the right thing to do.”