AAA reports that the national average price of gasoline increased 10.4 cents per gallon in May — the first monthly increase since February. In Montana, motorists are paying the highest price for gas the state has seen so far in 2013.

Nationally, gas prices have followed a roller-coaster ride. The national average increased 17 days in a row to $3.66 per gallon from May 6 until May 22 — the largest consecutive streak of price increases since February. The national average has since dropped nine days in a row to reach $3.61 per gallon today.

“What we’ve seen happening to the national average gas price this year has been unusual when compared to past trends,” AAA spokeswoman Kaelyn Kelly said. “Looking forward to the summer months, we usually expect prices to steady out or possibly decline through early summer, not rising again until late summer before hurricane season and the switchover to winter-blend gasoline.”

Prices in Montana and most Rocky Mountain states stayed far below the national average during the first part of the year. In Montana, prices reached a low of $2.99 per gallon on Jan. 27. Since then, they have been steadily rising to today’s year-to-date high of $3.65 — a few cents more than the current national average. Montana’s prices have more closely followed past trends of gasoline prices than the national average so far this year.

While it’s possible gas prices peaked for the year at $3.79 in February, there’s still potential for prices to spike later in the year, AAA reported. The organization said it has no record of gas prices ever previously peaking in February.

“When we talk about gas price predictions, we base those predictions off observing price trends from past years,” Kelly said. “Because 2013 has strayed far from the pattern of what tends to happen with gas prices, it becomes more difficult to accurately predict what they will do through the second half of the year.”

For more information, visit online at www.AAA.com.