First frost of season could hit parts of Northland on Tuesday morning

The frost advisory is posted for most of the region away from Lake Superior.

Frost on grass refraction Nov 4 2021 C S.jpg
The National Weather Service has forecast the first widespread frost across most of the Northland on Tuesday morning.
Contributed / Bob King
We are part of The Trust Project.

DULUTH — Bring in those sensitive plants in pots. Cover the ones you can’t move. And pick those last tomatoes.

The National Weather Service in Duluth is predicting the first widespread frost across most of the Northland on Tuesday morning, with a frost advisory posted for most of northern Minnesota and Northwestern Wisconsin.

Temperatures could dip into the upper 20s in parts of Koochiching County, like Bigfork and Big Falls, 31 degrees in Ely, Hibbing and International Falls and 34 degrees at the Duluth airport.

The exceptions to the frost advisory are areas near the relatively warm waters of Lake Superior where places like Two Harbors, Bayfield and Duluth and Superior harbors probably won’t drop below the mid-30s.

Frost is possible again Wednesday morning before a gradual warm-up later in the week, with highs in the 60s and lows in the 40s by Thursday and Friday.


Frost can occur even in the mid-30s depending on meteorological conditions. This year’s first of the season will be a little later than average for some areas of the Northland.

The National Weather Service in Duluth says the average first hard freeze, when temperatures dip to 32 degrees or colder, occurs Sept. 8 in Hibbing and Sept. 11 in International Falls, among the earliest in the state, with the average first freeze Sept. 14 in Mellen, Wisconsin, Sept. 21 in Brainerd and Sept. 30 at Duluth International Airport and Two Harbors.

John Myers reports on the outdoors, natural resources and the environment for the Duluth News Tribune. You can reach him at
What to read next
Temperature inversions, when a layer of warm air aloft covers cooler air below, are much more common during winter.
Temperatures may reach below 0° next week
Nature's beauty from a weather perspective
Water content, snow temperature and low humidity all slowed the snow melt.