After gas prices dropped to under $3.20 per gallon in many states back in September, we are seeing prices trickle up again.

With the exception of a few small dips, gas prices have been rising steadily since early February and have passed $4 per gallon in some parts of the country. According to GasBuddy, the national average is $3.59 per gallon, an increase of 3 cents per gallon from this time a week ago.

Motorists in a handful of states aren’t seeing gas prices go up much–people in Montana, for example, are seeing a decrease at the pump. The rest of us, however, are watching those numbers rise a few cents per gallon just as Spring Break kicks off for our kids. People in California are being hit the hardest, with gas prices exceeding $4 in some cities. Los Angeles motorists are paying a whopping $4.28 per gallon.

No surprise there, but unfortunately, analysts expect gas prices to keep going up for a little while.

Our research indicates that #gas prices will be on the rise this week. http://t.co/z3poPqfiic

— GasBuddy.com (@GasBuddy) April 14, 2014

If you’re wondering why you’re feeling the squeeze at the pump yet again since there are no hurricanes looming that could damage oil pipelines in the Gulf, it’s possible that an oil spill that occurred near the end of March is at least somewhat responsible for the increase.

An oil spill in Galveston Bay, Texas happened on March 22 when a ship hit a barge filled with oil. An estimated 168,000 gallons of oil was spilled into the ocean. A contributor for Forbes predicted that the oil spill would drive up gas prices at the time of the spill.

As you can see from the chart below, the national average has increased by 9 cents per gallon in the three weeks since the spill.

Oil refinery maintenance could also contribute to rising fuel costs, but analysts believe that things will get better at the pump around June. “Hotspots could certainly develop in any state over the next month or so as refiners finish maintenance, so motorists should be prepared for it, but once June rolls around, we will begin to see relief,” said Gregg Laskoski, senior petroleum analyst for GasBuddy.

Images via Wikimedia Commons and GasBuddy