NEW YORK (AP) — Oil prices rose slightly Monday, enough to close above $100 a barrel for the first time this year.

At the gas pump, prices appear to be starting their annual climb ahead of the U.S. driving season.

Investors are awaiting the first public comments from the new chairman of the U.S. Federal Reserve. Janet Yellen, who last week was confirmed in her role, is due to appear before U.S. lawmakers Tuesday and traders will be particularly interested to hear anything she says about the withdrawal of the Fed's monetary stimulus.

The central bank has reined in its stimulus program, but recent jobs data have suggested that the U.S. economic recovery may not be as healthy as seemed. The stimulus in its various guises has helped shore up a number of financial assets over the past few years, including oil prices.

Oil has been boosted recently by the frigid temperatures in many parts of the U.S., which has boosted demand for heating oil. That support could be waning.

"The recent price prop of exceptionally cold temperature trends has quickly given way to forecasts for significant moderation especially along the East coast," wrote Jim Ritterbusch, president of energy consultancy Ritterbusch and Associates, in a note to clients.

Benchmark U.S. crude for March gained 18 cents to close at $100.06 a barrel on the New York Mercantile Exchange.

U.S. drivers saw gasoline prices rise an average 2 cents over the weekend to $3.29 a gallon. Prices are expected to rise further as refineries undergo seasonal maintenance and then switch over to more expensive summer blends of gasoline. Still, the current average is 29 cents below where it was this time last year.

Elsewhere in oil markets, Brent crude, which is used to set prices for international varieties of crude, dropped 94 cents to $108.63 a barrel on the ICE Futures exchange in London.

In other energy futures trading in New York:

— Wholesale gasoline fell 2 cents to $2.72 a gallon.

— Heating oil shed 5 cents to $2.99 a gallon.

— Natural gas lost 20 cents to $4.58 per 1,000 cubic feet and has dropped 17.6 percent since closing at a four-year high of $5.56 on Jan. 29.