Denver gas prices began to climb last week and one expert said to expect the real increases to begin in a couple of weeks.

The average price of a gallon of gas in Denver on Monday was $2.64, a 17.6-cent increase week over week, according to a GasBuddy.com survey of 844 Denver stations.

Still, the prices are only 4.2 cents more than a month ago, the gas prices monitoring site said.

The national average ticked north as well, increasing 4.5 cents per gallon last week, and averaged $3.07 per gallon on Monday.

“We’ve seen the national average price of gasoline bounce back up after cold weather-related refinery shutdowns pushed up the wholesale price of gasoline,” Patrick De Haan, head of petroleum analysis at GasBuddy, said in a news release. “Plus, recent GDP data and new attacks in the Red Sea have pushed oil prices to their highest level since November.”

Statewide, prices were up 14.4 cents per gallon week over week in Colorado, with the average gallon selling for $2.72.

“While prices have inched up and may continue to slowly rise, I believe the larger increases will be witnessed in a few weeks as we enter mid-February, lasting through April or May, during which the national average could rise 35 to 85 cents per gallon,” De Haan said. “Other issues and tensions could complicate how quickly prices rise or how high they go, so while the rise is not completely charted, it could deviate from our expectations.”

Even with the recent increase, prices are still a relief compared with a year ago, when Denver was paying $3.78 per gallon — $1.14 cents more than today, GasBuddy said.