The national temperatures averaged 52.9 degrees — “4.5 degrees above the long-term average,” NOAA said in a statement. “Most of the contiguous U.S. was record and near-record warm for the six-month period, except the Pacific Northwest.” East of the Rockies, 28 states were “record warm,” NOAA said.

The past year also registered as the hottest 12-month period on record in the contiguous U.S., narrowly surpassing the mark set last month, NOAA said.