NEW YORK (AP) -- Gasoline prices have never been higher this time of the year.

At $3.53 a gallon, prices are already up 25 cents since Jan. 1. And experts say they could reach a record $4.25 by late April.

The surge in gas prices follows an increase in the price of oil.

Higher gas prices could hurt consumer spending and curtail the recent improvement in the economy.

A 25-cent jump in gasoline prices, if sustained over a year, would cost the economy about $35 billion. Economists say it's a meaningful amount, especially at a time when growth is only so-so.

Rockford, February 19- Average retail gasoline prices in Rockford have fallen 5.6 cents per gallon in the past week, averaging $3.46/g yesterday. This compares with the national average that has increased 4.5 cents per gallon in the last week to $3.51/g, according to gasoline price website RockfordGasPrices.com.

Including the change in gas prices in Rockford during the past week, prices yesterday were 26.8 cents per gallon higher than the same day one year ago and are 1.5 cents per gallon higher than a month ago. The national average has increased 17.1 cents per gallon during the last month and stands 35.0 cents per gallon higher than this day one year ago.

"Gasoline prices have perked up a bit in the last week," said GasBuddy.com Senior Petroleum Analyst Patrick DeHaan. "As we continue to move towards warmer weather, gasoline prices will follow, with prices accelerating higher at a faster pace come late March into April, so if motorists think this is bad, they should really hold on to their chairs," DeHaan said.