After months of barely budging more than a few cents, gas prices across the country have moved into the fast lane.
The national average for a gallon of regular gasoline spiked 12 cents since last week to hit $3.28 on Friday, according to AAA. That's 21 cents more than last month's average.
AAA says a significant factor driving up prices is a shutdown at the large BP-Whiting refinery in Indiana, which has been offline for more than two weeks due to a power outage. The refinery processes 435,000 barrels of crude per day, and the shutdown has caused prices throughout the Midwest to climb, pushing the national average higher as well.
"Pump prices usually move higher this time of year, but a 12 cent jump in one week is notable," Andrew Gross, AAA spokesperson, said in a statement. "However, the refinery shutdown will likely be resolved soon, so further increases at the pump should revert to slower and lower seasonal gains."
According to new data from the Energy Information Administration, gas demand decreased from 8.81 to 8.17 million barrels per day last week. Total domestic gasoline stocks declined by 3.7 million bbl to 247.3 million bbl (bbl refers to a barrel of crude oil, which is 42 gallons).
Lower gas demand would typically push pump prices down, but fluctuating oil prices and tight gas supply increase prices, AAA noted.
Hawaii currently leads the nation in high gas prices with an average of $4.70 per gallon, AAA reports.
Top 10 most expensive markets
1. Hawaii - $4.70
2. California - $4.64
3. Nevada - $3.90
4. Washington - $3.89
5. Oregon - $3.58
6. Pennsylvania - $3.55
7. Illinois - $3.49
8. Alaska - $3.46
9. Washington, D.C. - $3.41
10. Maryland - $3.36
The cheapest gas is in Wyoming, where the average price is $2.79 per gallon, per AAA.
Top 10 least expensive markets
1. Wyoming - $2.79
2. Oklahoma - $2.81
3. Kansas - $2.83
4. Mississippi - $2.85
5. Missouri - $2.87
6. Arkansas - $2.90
7. North Dakota - $2.91
8. Colorado - $2.92
9. Texas - $2.93
10. South Dakota - $2.92