WASHINGTON (MarketWatch) — The prices Americans pay for goods and services surged in January by the largest amount in four years, mostly reflecting a rebound in the cost of gasoline that’s taking a bigger chunk out of household incomes.

The consumer price index, or cost of living, rose by a seasonally adjusted 0.6% in January, the government said Wednesday. Economists polled by MarketWatch had predicted a 0.3% increase.

As has been the case lately, a big increase in the cost of gasoline accounted for almost half of the increase in consumer inflation in January.

The cost of filling up at the gas station has climbed to a nationwide average of $2.30 a gallon from just under $2 last spring, according to government figures.

The rising cost of gasoline is pinching U.S. households and pushing inflation higher after several years of little price pressures, a trend that could also spawn higher interest rates in the near future.

Over the past year the consumer price index has climbed 2.5%, the biggest increase in a 12-month span in five years.

For years low inflation had helped keep the Fed from raising historically low interest rates, but some top bank officials suggest the time has come to be more aggressive. Chairwoman Janet Yellen on Tuesday did not go that far in testimony in Congress, though she pointed out that inflation is no longer “at very low levels.”

Yellen left the door open for a rate hike in March.

The cost of gasoline appears to be leveling off, however, so it’s unclear if inflation will continue to creep much higher.

Still, gas is not the only staple that’s gotten more expensive. Rents have been rising rapidly and medical costs have increased.

While Americans shell out more for housing and health care, however, they are paying less for groceries. The cost of food rose slightly in January, but Americans are paying about 2% less for groceries now compared to a year earlier.

Stripping out the volatile food and energy categories, so-called core consumer prices advanced a slower 0.3% in January. The core rate has moved up 2.3% in the past year, little changed from the prior month.

The combination of mild increases in worker pay and higher inflation could put a damper on consumer spending moving forward. Real hourly wages fell by 0.5% in January, reflecting the squeeze put on consumers by higher gasoline prices.

Real or inflation-adjusted wages are flat over the past 12 months.