Gas prices in Colorado are spiking again – and this time, they’re breaking records.

Growing volatility in the Strait of Hormuz and low refining capacity in the U.S. have pushed crude oil prices past $100 per barrel for the first time since July, bringing prices at the pump back up to what they looked like in early June, according to a news release from the American Automobile Association.

The average national price for a gallon of regular gasoline climbed 14 cents in one week, hitting $4.29 on Friday, Sept. 11, according to AAA data. The average in Colorado sits roughly 5 cents higher per gallon, at $4.34.

While both the national and state prices for regular gasoline still sit notably below the record set in 2022 — created by heightened post-pandemic demand and supply constraints during Russia’s invasion of Ukraine — diesel prices across the country are officially at an all-time high.

“The structural pressures here are not necessarily unprecedented, but they are abnormal,” said Skyler McKinley, Colorado regional director for AAA. “What we’re watching to see is the extent to which abnormal transitions into unprecedented.”

The national average price for a gallon of diesel fuel reached $6.05 on Friday, climbing 8 cents in just 24 hours. The record set in Colorado was slightly lower, with a new high of $5.81 — roughly $2.25 more expensive than the state’s average price for diesel in September 2025.

For mountain towns on the Western Slope, the cost is even steeper. In Vail, diesel prices rose 10 cents overnight, hitting a record-high of $6.06 per gallon on Friday, according to AAA data. One year ago, the average price for diesel in Vail was $3.75. Diesel prices in Glenwood Springs sit at $6 as of Friday, $2.21 higher than last September.

“Diesel is the foundational fuel to the American economy. If you purchased something at a store, at a restaurant, online, it gets to you by semitruck. Those run on diesel,” McKinley said. “As diesel increases, you tend to see cost increases on everything else in our economy.”

Increases in diesel prices aren’t uncommon for this time of year, McKinley added. As the transition to colder weather drives up demand for heating oil — which has the same fuel composition as diesel — the strain is shared by diesel suppliers, driving up prices in the fall. International conflict has only added to the seasonal increases, with no promise of temporary relief.

“Prices may still climb on diesel fuel, which is tough for anybody in the trades, anybody who drives a diesel truck,” he said. “You hit an all-time high and then drivers expect relief, but there’s just upward pressure still on diesel. … There’s probably not relief in sight.”

For regular gasoline, September has historically meant lower prices as travel demand slows and gas stations begin switching to cheaper winter-blend gasoline. This year, that seasonal relief might not be enough to outweigh international pressures at the pump, McKinley said.

Additionally, although retailers can start selling cheaper winter-blend fuel after Sept. 15, it can take a few weeks for it to be fully priced in — especially in the mountains.

“You might see savings of 15 cents. Is that meaningful? Perhaps, although prices went up 13 cents in the past week alone based on those structural pressures. So I’m not sure … going from $4.45 to $4.30 is anybody’s idea of a great deal compared to where prices are typical at this time of year,” McKinley said. “We’ve seen all these other upward pressures lately that are geopolitical. If another medley of those kicks in at the same time that winter blend kicks in, you might not notice any savings whatsoever.”

Labor Day weekend should have been a cheaper travel period compared to the summer, based on historical price trends. Even with a softer travel economy leading up to the holiday weekend, however, Colorado experienced prices north of $4 for the first time in the holiday’s history, beating the 2012 record of $3.82.

“If you look at 20 of the past 26 years, prices were significantly lower a month after Labor Day than they were on Labor Day,” McKinley said. “This Labor Day, however, was the first time in Colorado we had prices north of $4 per gallon. So to an extent, the playbook is not as helpful right now as it would typically be.”