Oil futures rallied Friday, as a weekly decline in U.S. oil inventories, a drop in the number of active drilling rigs and data showing strong demand for gasoline helped prices for the U.S. benchmark log a second month of gains in a row. Traders were also considering the potential outcome of the Organization of the Petroleum Exporting Countries meeting on June 5.

On the New York Mercantile Exchange, July crude rose $2.62, or 4.5%, to settle at $60.30 a barrel. It was trading at $59.95 before the rig data were released Friday. Based on the front-month contracts, the U.S. oil benchmark saw a weekly gain of about 1% and monthly climb of 1.1%. July Brent crude on London’s ICE Futures exchange rose $2.98, or 4.8%, to $65.56 a barrel. Brent saw a weekly rise of 0.3% but lost about 1.8% for the month. The OPEC meeting is “definitely top of mind for traders and although expectations widely suggest OPEC will keep target output levels unchanged (which is obviously bearish for oil), there are a lot of market players not willing to carry the risk into the weekend,” said Tyler Richey, analyst for The 7:00’s Report. The cartel has an oil output ceiling of 30 million barrels a day.

Meanwhile, the number of U.S. rigs actively drilling for oil fell for a 25th week in a row, according to data from Baker Hughes released on Friday. The number of active oil rigs saw a weekly fall of 13 to 646 as of May 29. U.S. commercial crude-oil inventories fell by 2.8 million barrels in the week ended May 22, the U.S. Energy Information Administration said Thursday. It also showed a drop in gasoline supplies and revealed that implied demand for motor gasoline over the last four weeks averaged over 9.2 million barrels a day—the highest level since August 2007, according to Forex.com’s Fawad Razaqzada. “Traders realized that the summer driving season in the U.S. had started with a bang,” he said.

In other news, the biggest U.S. exchange-traded fund that tracks oil is heading for its largest two-month out flow in six years, a Bloomberg report noted. But flows for the United States Oil Fund and other popular crude ETFs shouldn’t be given as much credit or blame for oil’s moves as they often are, according to some industry insiders.