AAA released its latest Fuel Gauge Report, which said the national average price for a gallon of regular unleaded gasoline is $3.67, as of July 22. This price is 6 cents higher than on July 15 and 20 cents higher than on July 22 last year.

Certain regions in the U.S. are seeing much higher prices than others, for example states in the Midwest, Northeast, and Mid-Atlantic. Prices in the Midwest spiked last week, for example in Minnesota, prices increased 31 cents, they went up 32 cents in Indiana, and increased 33 cents in Missouri. Next, in 10 other states, Delaware, Connecticut, Maine, New Jersey, New Hampshire, Maryland, Massachusetts, Rhode Island, Pennsylvania, and New York, prices have increased 20 cents in the last two weeks.

The top states with the highest prices include Hawaii, at $4.35; Alaska, at $4.06, California, at $4.04; Connecticut, at $4.03; Illinois, at $3.95; Washington, at $3.94; New York, at $3.93; Oregon, at $3.89; D.C., at $3.87; and Rhode Island, at $3.81.

AAA said this increase was due to production concerns, partially due to operational problems at Irving’s Saint John Refinery in Canada. The company said market analysts believe the refinery won’t return to full production until after the summer driving season ends in September, which could keep pressure on prices in the region.

Regarding oil prices, West Texas Intermediate (WTI) has hit more than $100 per barrel each trading day since July 3, and hit a 16-month high of $108.05 on Friday, July 19. According to AAA, the increase in the price of WTI, the U.S. benchmark, has outpaced that of Brent crude, the European benchmark. In 2011, the price of Brent crude rose much higher than WTI because WTI was relatively insulated from geopolitical events that affected the price of Brent crude, according to AAA.

The gap between WTI’s and Brent crude prices has closed recently due to increased capacity to bring crude oil from the middle of the continent to the Gulf Coast where that oil can be sold at global prices. One example AAA gave was the reversal of the Seaway pipeline, which now brings 400,000 barrels per day of crude oil from Cushing to refineries on the Gulf Coast.