RICHMOND, Va. (WRIC) — Gas prices in the Central Virginia are on the rise again, and could soon blow past their March peak of $4.25 a gallon.

According to GasBuddy.com, average gas prices in the Richmond region recently hit $4.23 a gallon. That’s a 17 cent jump since just last week, and $1.36 more expensive than it was at this time last year.

May Gas Prices
(Chart courtesy of GasBuddy.com)

Gas prices hit an initial peak this year on March 10 in the immediate aftermath of the Russian invasion of Ukraine, reaching $4.25 a gallon before declining slowly over the next two months.

If last week’s trend holds, prices may soon surge past that peak.

The sudden jump may not be a result of geopolitics in Eastern Europe, however, but a result of an anti-smog law right here in the United States that restricts the sale of ethanol-blend fuel during the Summer months.

The so-called Summer blend – normally sold between May 1 and Sept. 15 – is about ten cents more expensive per gallon, but doesn’t evaporate in the heat as readily, meaning it contributes less to dangerous smog and greenhouse emissions during the hot Summer months.

President Joe Biden recently waived that rule for some stations this year, allowing them to sell the cheaper blend in an effort to drive down prices.

But that exception only applies to stations already selling a specific type of fuel called “E15,” which make up a small proportion of the gas stations in Virginia.

That means most have still had to switch over to the Summer blend, potentially contributing to the recent rise in prices.