HOUSTON — Gasoline prices reached a grim milestone on Saturday, as the national average for regular gasoline reached $5 a gallon.

Summer gasoline is nearly always more expensive because demand for fuel takes off around Memorial Day weekend. But this year oil and refined fuel prices have risen to their highest levels in 14 years, due largely to the Russian invasion of Ukraine and resulting sanctions, and a rebound in energy use as the economy recovers from the coronavirus pandemic.

The national average price of gasoline on Saturday was $5.00, up 60 cents from a month ago. A year ago, gas sold for $3.08, according to the AAA motor club. The national average has been at its highest point since March, when it went above its previous record set in July 2008, when oil was trading at more than $133 a barrel. That was more than ten dollars above the current level without even accounting for inflation. Back then, the national average gasoline price was $4.11, or about $5.37 a gallon in today’s dollars.

The average price is above $4 a gallon in all states. In California, long one of the most expensive states in the country for fuel, the price exceeds $6 a gallon. States with the largest recent increases in gasoline prices include Michigan, Delaware, Maryland and Colorado.

Energy experts estimate that every penny increase in the price of gasoline costs Americans an extra $4 million a day.

“Strap on for a sizzling summer ride,” said Tom Kloza, global head of energy analysis at Oil Price Information Service. “The average consumer is going to pay $450 a month for their fuel needs and that compares to something barely over $100 in 2020 during the pandemic.”

The war in Ukraine has had the most direct effect on gas prices, as sanctions on Russia have pulled more than a million barrels of oil off global markets. Energy traders have also bid up oil prices in anticipation that Russian production and exports will fall further.

But many other factors have contributed to the rise in prices.

There isn’t enough capacity to refine oil into gasoline, diesel and jet fuel. Oil companies closed a handful of refineries in recent years, especially during the pandemic when demand plummeted. A few new refineries will open or expand over the next year, which could help.

But for now, analysts say that strong demand for gasoline is straining limited supplies and pushing prices higher as drivers hit the road after several waves of new Covid-19 variants kept them close to home. The easing of stringent pandemic lockdowns in China has also pushed up oil prices.

The high gas prices — along with the rising costs for other necessities like food and shelter — are a big problem for President Biden. Many political experts believe the Democrats could suffer big losses in the November elections because voters are angry and frustrated about high inflation.

Last week, as gas prices edged closer to the $5 threshold, Biden administration officials said that the president would travel to Saudi Arabia, one of the world’s largest oil producers, in an apparent bid to restore diplomatic relations and, crucially, to seek help with bringing down energy prices. He is also encouraging domestic producers to pump more oil, although big oil companies are reluctant to increase investments significantly, preferring to return profits to investors through dividends and share buybacks.

In the past, when oil companies produced more oil in response to high prices, they caused a glut, undercutting their profits.

Mr. Biden has little influence on gas prices, which are governed by global supply and demand. Experts say even Saudi Arabia is not in a position to quickly bring down prices because it does not have the ability to completely offset the expected decline in Russian production. The European Union last month agreed to ban most Russian oil by the end of the year.

In March, when Mr. Biden announced that the United States was banning Russian oil and natural gas, he warned Americans that “defending freedom is going to cost.” There is some evidence that the high prices are beginning to have an impact on demand. Travel experts say that some people are choosing to drive shorter distances on their vacations.

Eventually the high prices at the pump are likely to encourage motorists to switch to electric cars, but the purchases of such cars are expected to reduce demand over the coming years, not months.

“It takes a while for price increases to affect demand,” said Donald Hertzmark, president of DMP Resources, a Washington-based energy consulting firm. “Consumers have to believe the price increases are real and permanent, and there has to be some period of adjustment to substitution, conservation and demand destruction.”

Clifford Krauss reported from Houston and Marie Solis reported from New York.