Gas prices across Ohio, Indiana, Michigan, Wisconsin, and Illinois jumped as much as 14 cents overnight, and a top fuel analyst warns the worst may not be over for a region already hammered by refinery shutdowns and global supply disruptions.
Patrick De Haan, head of petroleum analysis at GasBuddy, flagged the threat Thursday night in a post on X, placing Ohio at "high" risk for the largest price increases in the Great Lakes region. Wisconsin and Indiana drew "medium" risk ratings, while Michigan and Illinois sat at "low to medium", a designation De Haan raised to "elevated" for Illinois, Wisconsin, and Indiana by Friday. Newsweek first reported the overnight surge and De Haan's warnings Friday morning.
By Friday, AAA data showed the damage at the pump. Michigan drivers faced a statewide average of $4.89 a gallon, up 14 cents from Thursday and up $1.68 from the same day a year earlier, when the average sat at $3.21. Illinois averaged $4.85, Ohio $4.53, Wisconsin $4.41, and Indiana $4.00. Every one of those figures dwarfs what drivers in those states paid twelve months ago.
The immediate pressure traces to a pile-up of refinery problems across the region. ExxonMobil's Joliet refinery in Illinois, a key Midwest fuel supplier with a capacity of 275,000 barrels per day and output of roughly 11 million gallons of gasoline and diesel daily, went offline Sunday after flooding and a power outage knocked it out of service. ExxonMobil identified problems on primary and secondary ComEd power lines feeding the facility, Reuters reported. The refinery remained offline as of Thursday, and a safety flare triggered again on Wednesday.
ExxonMobil said power had been fully restored but did not say whether a subsequent pump problem was connected to the original outage. That leaves a basic question unanswered: when, exactly, Joliet will resume normal operations.
Meanwhile, Cenovus has scheduled major maintenance at its Lima refinery in Ohio, a 185,000-barrel-per-day facility, from September through mid-October. Energy markets analyst Brandon Noe Rivera Barron wrote on LinkedIn that the Lima outage has the potential to "reduce regional supplies of gasoline" at a time "when U.S. distillate inventories remain historically tight and refining margins are strong."
And then there is BP Whiting in Indiana, one of the largest refining facilities in the country, producing roughly 440,000 barrels per day. An unfolding labor dispute there raises the prospect of yet another disruption. The nature of the dispute, parties, demands, timeline, remains unclear.
Three major refineries offline or at risk simultaneously in a single region is not routine. Combined, Joliet, Lima, and Whiting account for 900,000 barrels of daily capacity. De Haan linked the price pressure directly to "continued refinery challenges" pushing wholesale gasoline costs upward across all five Great Lakes states.
The regional spike lands on top of a national surge that has steadily drained household budgets. The national average hit $4.47 a gallon Friday morning, per AAA, up from $3.20 a year earlier and $2.98 on February 28, the day the conflict with Iran began. That is a roughly 50 percent increase in barely six months.
De Haan posted on Bluesky Sunday that Americans have collectively spent more than $100 billion more on gasoline and diesel since March 1 compared with the same period a year ago. That figure, spread across every driver, commuter, trucker, and small business owner who fills a tank, captures the cumulative weight of a price environment that keeps grinding higher. The Iran conflict's cost to American households has been a running theme all year.
De Haan warned Thursday night that the increases were not done:
"These hikes would likely skew more towards tomorrow. Stations aren't yet paying these higher prices but will in a few hours... I'd look for them to start hitting tomorrow, but timing may vary."
That warning proved accurate. Prices moved overnight across all five states, and De Haan's Friday update escalated the risk level for three of them.
Refinery outages alone do not explain the national trajectory. The war in Iran has disrupted global oil supply chains since late February, and the Strait of Hormuz, through which roughly a fifth of the world's oil passes, has been effectively closed. A Houthi attack on Saudi Arabia forced the closure of a crucial oil pipeline, further tightening supply.
Those global disruptions have pushed crude costs higher everywhere. California leads the country at $6.11 a gallon, followed by Washington at $5.57, Hawaii at $5.49, Nevada at $5.22, Oregon at $5.11, and Alaska at $5.06. Even traditionally cheap states have felt the squeeze, Texas, now the cheapest in the nation, still averages $3.95.
For Great Lakes drivers, the combination is punishing: global crude prices elevated by conflict abroad, and regional supply pinched by three simultaneous refinery disruptions at home. The result is price increases that outpace the national average. Michigan's year-over-year jump of $1.68 a gallon and Wisconsin's $1.49 increase both exceed the national year-over-year climb of $1.27.
Families already adjusting to rising grocery bills and housing costs alongside fuel prices now face a regional premium on top of the broader national burden.
One detail captures how fast conditions have shifted. Indiana had been the cheapest state in the country for gasoline. After its 8-cent overnight jump to $4.00 a gallon Friday, Texas now holds that distinction at $3.95. A year ago, Indiana drivers paid $3.09. The state's proximity to the BP Whiting facility, and its exposure to a potential labor disruption there, makes the outlook worse, not better.
The broader pattern of record-breaking fuel costs driven by refinery strain has been building for months, and the Great Lakes region is now absorbing the sharpest edge of it.
President Trump addressed rising gas prices at a rally Wednesday in Gastonia, North Carolina, where he campaigned for Republican Senate nominee Michael Whatley. Trump told the crowd that gas prices would "come tumbling down" soon.
"That's gonna be like a rocket ship in reverse."
Trump characterized higher gas prices as "a very inexpensive price to pay" for ensuring that Iran does not obtain a nuclear weapon. The administration has framed the conflict as a necessary step to prevent a nuclear-armed Iran, a position that commands broad support in principle but faces growing pressure as the economic costs mount at the pump.
Since February 28, the national average has climbed nearly $1.50 a gallon. The surge past $4 a gallon earlier this year already strained budgets, and the current trajectory suggests relief is not imminent, particularly in the Midwest.
De Haan's Thursday night warning extended beyond gasoline. He noted a "moderate to large jump in diesel prices" was also likely for the Great Lakes states. Diesel powers the freight trucks, farm equipment, and delivery fleets that keep the Midwest economy moving. Higher diesel costs flow into the price of nearly everything consumers buy, from groceries to building materials.
Downstream effects from the energy crunch have already reached retail shelves. Costco nearly doubled the price of its Kirkland motor oil and capped weekly purchases as crude costs spiked, one example of how refinery disruptions ripple beyond the gas pump into everyday consumer goods.
With the Cenovus Lima maintenance stretching into mid-October, the Joliet refinery's restart timeline uncertain, and the BP Whiting labor dispute unresolved, the Great Lakes region faces weeks of constrained supply. De Haan has not responded to Newsweek's request for further comment sent Friday.
Michigan and Illinois both sit within striking distance of $5.00 a gallon. De Haan rated their risk of crossing that threshold at "low to medium", a classification that may sound reassuring until you remember that "low to medium" was the rating he gave Illinois, Wisconsin, and Indiana before upgrading all three to "elevated" the very next morning.
Americans can debate the strategic merits of the Iran conflict, but the household arithmetic is not debatable. Drivers in the Great Lakes states are paying 40 to 50 percent more per gallon than they did a year ago, and the analysts tracking the numbers say it is about to get worse. The people who set the policy are not the ones standing at the pump.