Gas may be cheaper or cost more in your state. Here's why.

With gas prices averaging more than $4 per gallon, drivers are wondering what causes price variances at the pump from state to state.

The queries come as the national average gas price rose to $4.08 per gallon on Thursday, April 2, according to the AAA Auto Club. That figure is up from a national average price of $3.98 one week ago, on March 26, and an average of $3.00 on March 5.

The state with the highest gas prices on April 2 is California, where drivers paid an average of $5.89 per gallon, which was up from $4.65 one month ago on March 5. The state with the lowest gas prices on April 2 was Oklahoma, where drivers paid an average of $3.27 per gallon, which was still up from an average price of gas in Oklahoma of $2.47 per gallon one month ago on March 5.

The USA TODAY Cars Team looked at the causes of variation in state gas prices and which states have the highest gas taxes.

Regional differences in gas prices can be explained by several factors, according to the U.S. Energy Information Administration.