The national average for gasoline is currently at $3.66 per gallon and has stagnated around $3.60 since April 9 — after it crossed that threshold for the first time this year, according to WEX Inc. It is roughly 6 cents more expensive than last year, but prices are very divergent regionally. Currently, 23 states are seeing averages at least 10 cents greater than the same time in 2013.

Pennsylvania has the largest year-on-year surplus with its current average of $3.757 per gallon ― more than 25 cents higher than last year. South Carolina, Kentucky, Nevada and North Carolina all have averages more than 20 cents higher than last year.

In contrast, some states are seeing lower prices compared to last year. In North Dakota, prices are more than 40 cents per gallon lower than in 2013. And prices in Iowa, Minnesota, Colorado, South Dakota and Nebraska have averages at least 30 cents per gallon less than last year, says WEX.

Most experts believe prices have peaked for the spring and June should see prices decline, according to WEX. Although this is a pattern witnessed over the last several years, market-watchers think that a second surge could come toward mid-to-late summer.

The summer-drive season is expected to be strong, which could put pressure on supplies and propel prices higher, especially if an active hurricane season starts to threaten the Gulf Coast and the refining sector.

Meanwhile, diesel prices have held steady at $3.90 per gallon. Analysts believe that diesel prices are likely to drift lower, as well, according to WEX.