Average gasoline prices across all fifty states increased in the last week as the national average jumped 25 cents to $2.64 per gallon in the biggest weekly rise since 2005 when the effects of Hurricane Katrina led prices to soar 49 cents in a week.

“Thanks to Harvey shutting down an extensive amount of refining capacity, the national average gasoline price saw its largest weekly jump since Katrina hit the Gulf Coast in 2005 when the national average jumped 49 cents in a week. Every state has seen average gas prices rise and Texas saw shortages at hundreds of stations. It’s been one of the most challenging weeks faced in years,” said Patrick DeHaan, senior petroleum analyst for GasBuddy.

“Until Texas can recover from Harvey, gasoline prices will likely continue to remain elevated. The situation is beginning to look up with many refineries either back online or in the process of coming back online resulting in gasoline production ramping back up. While it may be weeks or longer before all refineries are back online, we now turn our attention to Hurricane Irma. With the Colonial Pipeline shutting down last week due to a lack of products, Florida, the Southeast and the Mid-Atlantic region may be a touch-and-go area for gasoline. Products are flowing to the region but we’ll have to keep a close eye on the storm as Irma’s path continues to be updated. GasBuddy has expanded its emergency gas availability tracker to Florida, Georgia, and the Carolinas. Also, we are prepared to expand the coverage of that tracker if motorists need help finding gas in other areas. Much remains in the air, but the situation promises to be challenging if Irma threatens the U.S. mainland,” DeHaan added.

The pinch at the pump was a direct result of Harvey: immense rain flooded refineries, wind and waves closed vital ports, there were massive disruptions to oil refineries of which more than a dozen shut down closing over a quarter of the country’s refining capacity. It was a major disruption to gasoline production resulting in gas prices spiking across much of the country with the biggest increases generally east of the Rockies.

Eighteen states saw average gas prices rise by over 30 cents per gallon versus a week ago, while these ten states saw the largest weekly rise: Delaware (+42 cents), New Jersey (+39 cents), Georgia (+38 cents), Maryland (+38 cents), New Hampshire (+38 cents), Tennessee (+37 cents), Connecticut (+37 cents), Massachusetts (+37 cents), South Carolina (+36 cents) and North Carolina (+36 cents). The ten states that saw the smallest increases: Hawaii (+0.2 cents), Utah (+3 cents), Idaho (+5 cents), Oregon (+6 cents), Alaska (+6 cents), Washington (+7 cents), Nevada (+7 cents), Michigan (+8 cents), Arizona (+9 cents), Montana (+9 cents), Indiana (+10 cents).

States with the lowest average gasoline prices today: South Carolina ($2.37), Louisiana ($2.38), Arkansas ($2.40), Missouri ($2.41), Mississippi ($2.45), Arizona ($2.45), Kansas ($2.46), Alabama ($2.50), South Dakota ($2.50) and Minnesota ($2.50).

While oil prices saw little change last week, gasoline prices soared as the choke point became the nation’s refineries. Oil inventories did fall 5.4 million barrels, as reported by the Energy Information Administration, with inventories now 7.6% lower than a year ago. Gasoline inventory data, which did not yet include any disruption from Harvey, were unchanged, 1% lower than a year ago. It is likely that when the EIA’s weekly report is released Thursday, the data will reflect Harvey’s shut down of refineries and gasoline demand that likely spiked as motorists filled their tank before the storm.

Looking at gasoline prices in the coming week, the biggest increases to the national average are behind us. While prices may tiptoe higher in some states for several more days at least, the national average is likely to peak later this week. Motorists in some areas may start to see relief as refineries get back online and gasoline begins to flow again. However, with Hurricane Irma’s track hard to nail down, there may be varying impacts as a result. Gas prices are unlikely to see a similar increase with Irma if the storm does not target the sensitive heart of the Gulf, where much of the South’s oil infrastructure stands.

Head of Petroleum Analysis (USA)

Patrick has developed into the leading source for reliable and accurate information on gas price hikes. Patrick has been interviewed as a gasoline price expert hundreds of times since 2004. Based in Chicago, Patrick brings to GasBuddy all his assets to help consumers by giving reliable and accurate price forecasts, including the San Jose Mercury News dubbing Patrick "one of the nation's most accurate forecasters" in 2012.