Gas prices have gone up in the past two weeks and in time for the Easter holiday weekend.

Prices have been trending upward lately, showing signs of their typical springtime volatility, AAA reports.

“With the advent of spring, people are driving more, which boosts demand,” said Chuck Mai, spokesman for AAA Oklahoma. “Refineries have begun producing more expensive summertime blends, there’s still some uncertainty over OPEC’s extension of production cuts and the market continues to be skittish over the U.S. bombings in Syria. While Syria is not a major oil producer, many of its neighbors are.”

AAA forecasts the Oklahoma pump price average will hit a peak of $2.40 this summer and the national average will top out at $2.70.

The nation’s top 10 markets with the largest weekly increases include Kentucky (+15 cents), Florida (+12 cents), Michigan (+12 cents), Indiana (+11 cents), Alaska (+10 cents), Missouri (+9 cents), Pennsylvania (+9 cents), Illinois (+9 cents), Georgia (+7 cents) and Colorado (+7 cents)

The nation’s top 10 least expensive markets are South Carolina ($2.11), Alabama ($2.14), Tennessee ($2.14), Mississippi ($2.14), Oklahoma ($2.15), Arkansas ($2.16), Virginia ($2.19), Louisiana ($2.19), Missouri ($2.20) and Texas ($2.21).