While conditions in Northwest Montana are abnormally dry, portions of eastern Montana are facing drought conditions they haven’t seen in over 50 years. Meteorologist Richard Heim is responsible for drafting Montana’s most recent drought map and explains the difference designations.

“It is basically a measure of how rare the condition is,” said Heim. “A D-1 has to have a severity once every five years to once every ten years, down to D-4 which is severity of dryness that happens statistically on average once every 50 years, once in 100 or once in a 1000.”

More than half of Montana is currently in some form of drought. Heim describes the map starting with areas classified as D-4, the most extreme drought.

“There is D-4 in the very northeast county which is Sheridan,” Heim said. “There is D-4 straddling the Missouri River right around Fort Peck. D-3 spans basically the northeast third of the state. D-2, which is severe drought, spans the whole eastern almost half of the state.”

Montana’s drought conditions will likely trigger some federal aid. Late Wednesday, Governor Steve Bullock made a drought disaster declaration for 22 counties and five reservations.