Wisconsin drivers got hit with a 16-cent overnight jump at the pump, with the statewide average for regular gas rising from $3.81 on Tuesday to $3.97 by Wednesday. Some corners of the state saw it worse: La Crosse hit $4.03 a gallon, Wausau climbed to $4.08, and Superior topped out at $4.17 in the September 9 regional figures, according to price tracking cited in the original report.
Crude Oil Breaks $100 as Tanker War Escalates
The spike traces back to the Middle East, where international benchmark Brent crude breached $100 a barrel on Wednesday for the first time since July 24, according to Al Jazeera. The price surge followed a U.S. Central Command retaliatory operation on Tuesday that targeted five named Iranian crude oil carriers in the Gulf of Oman — the M/T Kaviz, M/T Charminar, M/T Horizon 1, M/T Riesco, and M/T Derya — including the M/T Riesco, which sank, as reported by Anadolu Agency. U.S. Central Command said the strikes were retaliation after two Navy warships were hit by Iran's Islamic Revolutionary Guard Corps on September 5, according to the Milwaukee Journal Sentinel, which also reported the U.S. destroyed another Iranian tanker near Kharg Island the same day, according to USA Today.
Iran responded with a retaliatory missile barrage against Jordan's Muwaffaq Salti Air Base overnight into Tuesday, where Jordanian air defense systems intercepted 18 Iranian missiles, per CBS News. The air base hosts U.S. military operations in the region, adding another layer of risk to a conflict that's already rattling energy markets. Marine traffic faced security risks in early September amid the naval combat and threats around the Strait of Hormuz, per Al Jazeera's separate reporting on the chokepoint, through which roughly 20 percent of global petroleum consumption flows.
Regional Averages Swing Across the State
The pain wasn't evenly distributed. Milwaukee's average climbed to $3.87 a gallon Wednesday, up from $3.73 the day before, while Kenosha County saw one of the sharpest local jumps at 22 cents, landing at $3.89. Madison rose 16 cents to $3.98, Green Bay climbed 19 cents to $3.93, and Sheboygan jumped 21 cents to $3.98 — all figures reported in the Journal Sentinel's tracking of Wednesday's statewide numbers.
Diesel prices told a similarly grim story. Wisconsin's average diesel price sat at $5.75 a gallon Wednesday, still below the state's record of $5.87 set on May 13, according to AAA figures cited in the same report. Nationally, diesel averaged $5.94 a gallon, and the national average for regular gas hit $4.22, up 7 cents on the day. Wisconsin's August gas price record of $3.91, set on August 13, had already eclipsed the state's previous August high of $3.70 from 2022 — a sign of how much pressure pump prices have been under all summer. According to the U.S. Energy Information Administration, monthly and annual averages in its Midwest gasoline and diesel retail-price series are simple averages of weekly data.
Why Wisconsin Feels It Faster
Wisconsin prices can swing hard, so fast, in part because of geography. That pressure was already showing up before this week's spike — Wisconsin prices were also rising heading into Labor Day weekend.
Patrick De Haan previously said each day the Strait of Hormuz is effectively closed to shipping could add an additional week to the timeline for gas prices to recover, a warning that looks increasingly relevant with shipping now disrupted around the strait.
State Law Keeps a Floor Under Prices
Even if wholesale costs ease, Wisconsin law prevents stations from passing full relief on to drivers right away. Under the state's Unfair Sales Act, retailers must apply a cost-based minimum markup of 6 percent to motor fuel, while wholesalers face a 3 percent markup. On top of that markup floor, Wisconsin charges a 32.9-cent-per-gallon fuel excise tax plus a 2-cent petroleum inspection fee, a combined rate that has been frozen since lawmakers eliminated automatic inflation indexing back in 2006, per Civic Media. Federal gas taxes add another 18.4 cents per gallon, a rate that has not moved since 1993, according to the U.S. Energy Information Administration. According to Wisconsin Legislative Documents, Wisconsin's Unfair Sales Act, also known as the minimum markup law, requires wholesalers to include a minimum markup in sales to retailers.
Efforts to repeal Wisconsin's minimum markup law have been discussed as a way to lower gas prices. Whatever the status of repeal efforts in Madison, the statutory floor remains in place even as crude oil volatility drives prices in the opposite direction. For now, Wisconsin drivers are left absorbing both the geopolitical shock and the state's built-in pricing rules at the same time.
