U.S. Gas Prices Dip Below $4 a Gallon for First Time Since March

U.S. gasoline prices have dropped just below $4 per gallon for the first time since March, averaging $3.999 nationally as of June 18, 2026, according to AAA. The decline follows a 15% drop in crude oil prices this month and comes after President Donald Trump signed an agreement with Iran that includes Tehran diluting its highly enriched uranium stockpile and a partial lifting of U.S.-backed sanctions. While the national average is now below $4, regional disparities remain stark: California’s average sits at $5.64 per gallon, while South Carolina’s is $3.58. Analysts caution that the full benefits of lower oil prices may take weeks or months to reach consumers due to ongoing disruptions in the Strait of Hormuz, where hundreds of trapped ships and cautious shipping companies delay the resumption of crude flows. Refineries, which typically purchase crude a month or more in advance, will also need time to process cheaper oil. The agreement between the U.S. and Iran aims to permanently end hostilities and includes a 60-day negotiating period to finalize terms on Iran’s nuclear program, though the door remains open for renewed military action. Oil prices have fallen to about $80 per barrel for U.S. benchmark crude, down from over $120 earlier in the conflict and $67 before the war. Despite the recent dip, gas prices remain 25% higher than the same period last year. Diesel prices are also expected to fall below $5 per gallon in the coming weeks. The Strait of Hormuz, which previously carried one-fifth of the world’s crude oil, remains disrupted, with supply chains for fertilizer, food, and other goods still feeling the ripple effects of the conflict.