An Arctic cold blast that swept through the U.S. South in February caused a much bigger loss in oil supply than previously estimated, with output falling to a three-year low, according to U.S. government data. Drillers cut oil production by almost 1.2 million barrels a day, the biggest decline since May and far more than the 800,000 barrels a day officials had estimated in early April, according to figures released Friday by the U.S. Energy Information Administration.

Cold Hit

U.S oil output declined more than initial estimates for February

Source: EIA

NOTE: EIA originally expected February crude output to decline 800,000 barrels a day.

Scores of wells were forced to shut after extreme cold triggered power outages across Texas, the nation’s energy capital. The historic wintry blast at one point curtailed about 4 million barrels a day of U.S. crude oil supply, traders and executives said at the time. The low temperatures also froze oil and gas output at the well head, along with pipes that were transporting that supply.