Just as forecasters had been predicting for nearly a week, much of the Northand woke up to its first frost of the season on Tuesday morning, with temperatures dropping into the 20s in some areas.
The automated reporting station at Grand Marais/Cook County Airport reported 27 degrees at 5:30 a.m., among the lowest readings in the state.
Other reports included 31 degrees at Isabella and Cotton, 32 at Hibbing and Ely, 33 at International Falls and Superior and 36 degrees at Duluth International Airport, according to data from the National Weather Service in Duluth.
Frost can occur at temperatures of about 35 degrees and lower while a full-scale freeze occurs below 32 degrees.
The first frost comes a bit earlier than the long-term average. Ely on average sees its first 32 degree reading on Sep. 20 while Duluth on the hill sees its first 32 or lower temperature on average about Sep. 27 and International Falls on Sep. 16.
Freeze warnings are posted again for Wednesday morning north of Duluth with frost advisories posted for Duluth, the North Shore and Northwestern Wisconsin, with temperatures again expected to drop into the lower 30s and even upper 20s. A gradual warming trend is on the way for later in the week.