Total U.S. oil production has plunged by close to 40% — the most ever — as an unprecedented cold blast freezes well operations across the central U.S., according to traders and industry executives with direct knowledge of the operations.

U.S. oil production has plunged by more than 2 million barrels a day as the coldest weather in 30 years brings havoc to key producing states that rarely have to deal with frigid Arctic blasts.