Coal production dropped the most since President Trump was sworn into the Oval Office nearly one year ago, according to new federal data issued this week.
The plunge occurred at the end of last year on Dec. 30, falling 36 percent compared to the day after Trump was sworn in as commander in chief.
Trump has boasted that coal production is up since he took office. But the Energy Department's analysis arm showed that it has mostly ebbed and flowed all year, with a huge drop occurring over the holidays.
The day after Trump took office, U.S. coal production jumped by 1 million short tons from 15.4 million short tons on Jan. 14, 2017, to 16.4 million metric tons on Jan. 21, according to the Energy Information Administration, the Energy Department's independent statistical and analysis wing.
Production then varied through the year before plummeting to 10.4 million short tons on Dec. 30, 36 percent less than Jan. 21, when Trump took office, EIA data showed.
It picked up a bit by the end of the week ending on Jan. 6 to end at about 12.1 million short tons, which is about 10 percent lower than the same week last year.
One explanation could be the Arctic chill that drove up coal demand but may have slowed production, according to National Mining Association spokesman Luke Popovich.
"It fell on the holiday period, plus they may not have gotten all the car loading data," Popovich said.
"Or could be weather related," he said in an email.
However, he conceded that he was not certain what the reason for the drop may have been.
Data on how much coal was used during the two-week deep freeze is expected to be released later this month. The cold snap that affected the East began the last week of December and lasted through the first week of January.