CHARLOTTE – Gas prices are still below last year’s average of $3.61 per gallon, but have spiked in the past month from $3.38 to $3.54, according to AAA Carolinas.

Prices in North Carolina varied greatly. A gallon of gas dipped to $3.22 per gallon on Dec. 20. On April 6, it hit a high of $3.91.

The price hike is due to higher crude prices as well as refineries switching to summer blend gasoline, which restricts output and tightens supply.

In South Carolina, gas prices are averaging $3.35 per gallon Feb. 12, up 14 cents from a month ago, but still 6 cents cheaper than a year ago.

Nationally, the average is $3.60 this week, up 20 cents from a month ago and up 9 cents from a year ago.