Gas prices are on the rise again. Here’s where experts say they are going next.

Budget-conscious motorists may want to fill up sooner rather than later, as prices at the pump are likely headed higher in the near term.

The approach of the peak driving season and the annual switch by refineries to more costly summer gasolines has driven up the national average for unleaded to $3.63, according to AAA.

Prices have been edging higher, with motorists on average paying six cents more per gallon than a week ago and 23 cents more this time last month. Still, the cost of filling up is in line with where motorists and their wallets stood a year ago, when a gallon of unleaded came to $3.61, AAA data shows.

The cost of gas proved to be a large factor in the surprise jump in inflation last month — a trend that is likely to persist in April, experts told CBS MoneyWatch. Paying to keep vehicles running and a roof over one’s head accounted for more than half the March rise in the consumer price index, which rose 3.5% last month from a year ago. Gas prices increased 1.7% from February to March, the government data released on Wednesday showed.

Why are gas prices rising?

Underlying the higher costs of gas are routine factors including refinery maintenance, the switch to summer gasoline and rising demand. Added to the mix are geopolitical factors, including the Russian-Ukraine war and Israel’s war against Hamas in the Gaza Strip, which has spurred the price of oil to six-month highs.

U.S. intelligence that Iran is preparing to retaliate for the Israeli attack early last week on an Iranian consulate in Syria is among the developments keeping the global commodities market on edge.

Defense Secretary Lloyd Austin has urged Ukraine against further attacks on Russian oil refineries, citing the risk to global energy markets, the Biden administration official told Congress on Wednesday.

“The West Coast is likely to see gas prices continue to jump, and in a week or so, will be joined by the mid-Atlantic and Northeast states as they wrap up the transition to summer gasoline,” GasBuddy noted Monday in a blog post.

Gas prices are averaging $5.41 a gallon in California and topped four bucks a gallon in half a dozen states, including Alaska, Hawaii, Illinois, Nevada, Oregon and Washington, according to AAA. The least expensive gas can be found in Arkansas, Colorado, Mississippi, where a gallon is averaging under $3.20.