California diesel returned to $7 a gallon and the U.S. average reached about $5.50 as attacks on Russian refineries, Middle East refinery outages and disrupted Strait of Hormuz flows tightened global supplies. The national average rose to $5.5042 a gallon on Wednesday from $5.4677 on Tuesday, while California reached $7.0066. California prices are about 30 cents higher than a month ago and $1.89 above the same period in 2025; nationwide prices have risen about 40 cents over the month and $1.81 year over year. The diesel crack spread reached a record $102 a barrel, highlighting extreme refining margins as analysts warn that higher transportation, farming and heating costs will raise consumer inflation. California Gov. Gavin Newsom also accused President Donald Trump of allowing the Iran conflict and Strait of Hormuz closure to impose an $86 billion fuel burden on Americans while benefiting Big Oil.