Over the past month, Arizona has seen the biggest increase in average gas prices in the country. The average price as of March 9, 2023, is nearly $3.90 a gallon — about 42 cents above the national average. Phoenix is seeing even higher averages.

Patrick De Haan with GasBuddy says the higher prices are due in part to the normal seasonal transition to the more expensive clean burning gasoline required under law.  

"In addition, refineries in the West Coast, especially southern California, where Phoenix gets much of its gasoline, is doing maintenance, and that limits the amount of supply available," De Haan said.

He also says these high prices could last through May.

According to AAA Arizona, gas prices in the state have been above the national average for the last year.