It’s been a welcome relief at the pump for drivers in Denver. Gas prices have tumbled significantly over the last month, and while one analyst says he expects the trend to continue, he’s also keeping his eyes on one factor that could send prices in the other direction.

“While the price of oil jumped some 5% last week, I remain steadfast that additional declines are coming to gasoline prices the way the situation stands now,” Patrick De Haan, head of petroleum analysis at GasBuddy, said Monday in a news release. “But (I) remain cautious that this depends on actions that are not foreseeable, mainly the conflict in the Middle East.”

The average cost of a gallon of gasoline fell 12.3 cents last week in Denver and stood at $3.52 on Monday, according to a GasBuddy survey of 844 stations across the Mile High City.

That price is 43.1 cents per gallon lower than it was a month ago, and flat when compared with the price a year ago.

Nationally, GasBuddy said prices saw “downward momentum” with the average falling nearly across the entire country, according to its survey of more than 150,000 gas stations nationwide.

“For now, the national average is likely to soon fall to its lowest level in six months,” De Haan said. “I believe the national average still has some 15-35 cents of declining to do the way things stand now.”

Diesel prices also came down last week, falling 6.8 cents per gallon to a $4.41 national average on Monday, Gas Buddy said.