The price of a gallon of regular gasoline has fallen below $4 a gallon in the Portland area for the first time in 10 months.

Metro residents are paying $3.93 a gallon at the pump this week, according to AAA. Gas prices have been in a steep decline since October, when metro residents were paying $5.64 a gallon, a record high.

The relief comes as Oregonians embark on holiday road trips — and just ahead of an expected cold snap that could leave roads covered in snow on Thursday and icy and hazardous on Friday.

Across Oregon, prices dipped below the $4 a gallon threshold earlier this month and hit $3.82 this week. Nine of the states most rural counties are still paying more, though, the highest among them Baker County ($4.62), Curry County ($4.56) and Union County ($4.42).

Gas prices have plummeted nationwide following the price of crude oil, which fell below $72 per barrel this week. That’s the lowest price since last December.

AAA said shorter days have also cut back on driving, and the nation’s stock of refined gasoline has increased, helping push gas prices lower. They’re expected to continue to fall in Oregon and most other states over the next several weeks. The national average, now $3.25 a gallon could dip below $3, the organization said.

Oregon has the fifth most expensive gas in the nation, but prices are also among the fastest to decline. The state reported ninth-largest week-over-week drop.