Gas prices have been going back up again. In North Dakota, it's risen an average 8.5 cents per gallon in the past week.
Analysts say it's normal when the weather starts warming up.
That's when the annual switch from winter to summer blends requires more refining and higher prices.
“Energy is produced year round and supplies are stock piled in the winter time and are used aggressively as we head towards the summer, so the refining capacity is not capable of meeting all those needs in the summer time, they refine it in the winter time and store it, so you are now utilizing those supplies,” said Heartland Investors analyst Eugene Graner.
Graner also added the political turmoil in Venezuela also affects prices, as well as OPEC restricting some of its supplies.