The average price of diesel fuel in the United States topped $5 per gallon on July 16, 2026, rising from $4.9380 just one day earlier, according to AAA data. Regular gasoline is closing in on $4 per gallon. The jump follows Iran's declaration earlier this week that the Strait of Hormuz is closed to shipping, a move that has shaken global energy markets and pushed crude oil to roughly $81 per barrel.

The Strait of Hormuz is a narrow passage at the mouth of the Persian Gulf through which about a fifth of the world's daily oil supply travels. Think of it as a toll booth on a highway: if it shuts down, a huge share of global oil traffic has nowhere to go. Before this week, both Iran and the United States had positioned themselves as guarantors of safe passage through the waterway. That understanding fell apart when Iran declared the strait shut, prompting the US to announce a blockade on all ship traffic to or from Iranian ports.

The escalation moved quickly. On Monday, July 13, President Trump announced that the United States would take over the Strait of Hormuz and charge a toll equal to 20% of the value of any cargo passing through. He later dropped that plan. The sequence of events unfolded over days: a unilateral toll proposal, its retraction, an Iranian shutdown declaration, and a US counter-blockade. Together, they have left the legal and operational status of one of the world's most critical shipping lanes in question.

The AAA national averages as of July 16, 2026, tell the story across fuel grades. Regular gasoline sits at approximately $4 per gallon, up from $3.8900 on July 15. Mid-grade gasoline averages $4.4480, premium averages $4.8290, and diesel has crossed the $5 threshold to $5.0050. E85, an ethanol blend, remains the cheapest option at $3.0330.

The diesel price trajectory over the past month shows volatility rather than a steady climb. On June 16, the AAA national average for diesel stood at $5.1850, higher than today's level. It then fell to $4.8100 by July 9 before surging more than 19 cents over the following week. The single-day jump from $4.9380 to $5.0050 between July 15 and July 16 coincides with the heightening Hormuz crisis.

Historical Context and Comparisons

Today's diesel price of $5.0050 remains below the all-time AAA national average record of $5.8160 set on June 19, 2022. Regular gasoline is well below its record of $5.0160 from June 14, 2022. But the year-over-year comparison is sharp: on July 16, 2025, diesel averaged $3.72 per gallon and regular gasoline averaged $3.16. Today's regular price is roughly $0.84 higher than a year ago, and diesel is up approximately $1.28.

The price movements of recent months trace the arc of US-Iran tensions. In late April 2026, AAA reported a near-30-cent weekly jump in the national average for regular gasoline due to spiking oil prices. By early May, the average surpassed $4.50 for the first time since July 2022. Memorial Day weekend saw a four-year high of $4.56 per gallon, $1.38 above the same holiday in 2025.

Prices then retreated through June as Washington and Tehran worked toward a long-term deal, with AAA reporting crude oil prices were falling. The national average for regular dropped below $4 on June 18, reaching $3.99, its first sub-$4 reading since March 30, 2026. The Associated Press attributed the decline to a 15% drop in US crude prices. By June 25, AAA reported the average at $3.91, holding below $4 for a second consecutive week. Reuters recorded a sixth straight week of declining prices on June 22, at $3.85.

That downward trend has reversed sharply. By July 3, GasBuddy projected a July 4 average of approximately $3.75. Two weeks later, on July 14, Reuters reported the national average had risen to $3.84, up 9.8 cents in a week. AAA's July 16 figure of nearly $4 per gallon for regular continues that climb, and diesel has now breached $5.

Regional Variation

Fuel prices vary widely by state. In Alaska, AAA reports regular gasoline at $4.6710, mid-grade at $4.9090, premium at $5.0990, and diesel at $5.2440. Alabama's regular average is $3.5880. Colorado shows regular at $3.8840, mid-grade at $4.2880, premium at $4.6350, and diesel at $4.6310. The District of Columbia's record averages, from June 2022, remain extremes: $5.2620 for regular unleaded and $6.2280 for diesel.

What Comes Next

The broader question is whether the Hormuz shutdown and US blockade represent a temporary escalation in a negotiation or a lasting disruption to maritime commerce. The June price decline was driven by expectations of a US-Iran deal; this week's reversal suggests those expectations have flipped. With both the Iranian closure and the American blockade announced but their enforcement mechanisms unclear, the gap between declaration and operational reality is where energy markets will find their next direction.

For US consumers and the logistics sector, the diesel breach above $5 carries particular weight. Diesel powers freight transport, agriculture, and industrial supply chains. A sustained price at this level feeds into broader inflation dynamics at a moment when the Federal Reserve is already navigating competing pressures. The crude oil price of approximately $81 per barrel has not yet spiked to levels that would suggest full market panic, but it has moved decisively off the lows that enabled June's price relief.

The Trump administration's rapid withdrawal of the cargo toll proposal suggests an awareness of the political and economic exposure created by a prolonged Hormuz disruption. Whether that instinct produces a de-escalation or merely a tactical pause is the open question facing oil markets, shipping insurers, and anyone filling up at the pump.