Retail gas prices across the nation creeped up 8 cents, the first increase in about three months, according to a survey released Sunday.

The weighted average price for all three grades climbed to $2.24 a gallon on Dec. 16, said Trilby Lundberg, who publishes the semimonthly Lundberg Survey of 7,000 gas stations around the country.

Self-serve regular averaged $2.21 a gallon nationwide. Mid-grade cost $2.31 a gallon while the price for premium was $2.41.

Prices at the pump have fallen about 88 cents since September, Lundberg said.
Among stations surveyed, the lowest average price in the country for regular unleaded was $1.98 a gallon in Salt Lake City. The priciest was in Honolulu at $2.57.

In California, the average price for self-serve regular was $2.21 a gallon. The best deal was in the San Francisco Bay area at $2.16 a gallon. The most expensive was in San Diego at $2.28.