Fog Covers Duluth Amid Warm Start to Summer

DULUTH, Minn.– The early summer heat, along with the impact of Lake Superior, has been creating some weather phenomena around Duluth.

“That marine can influence a lot,” said NOAA Meteorologist Dean Melde. “More early in the season in the summer and then over the winter before we start seeing some ice.

If you were anywhere close to the waters of Lake Superior on Thrusday, there’s a good chance you saw a thick layer of fog. Just another one of the lake’s weather tricks here in early summer.

A stretch of unusual weather brought a blanket of fog into Duluth Thursday, rolling in from Lake Superior anywhere from west Duluth to London Road.

“Lake superior adds a lot of complexity,” said Melde.

Over at the National Weather Service in Duluth, Melde says the unusually warm temperatures and high dew points from the last week played a big role. The chilly waters of Lake Superior cool down the dew points over the lake to create a cloud over the lake we call fog.

“The lake is still cold. It’s in the 50s,” said Melde. “You lift the cloud and it cools. And when it hits the dew point, you get a cloud that forms. So it’s kind of like that process over the lake where the lake is what’s cooling the temperatures to the dew point. When that happens, you get the fog that forms.”

Then when the temperatures cool down late in the year, Melde says the warmer lake water mixed with the cold air creates a steam effect over the water.

The fog can be pushed well into land from the lake as much as 20 miles depending on wind conditions.

“The wind does play a big role,” said Melde.

The fog may be something Duluthians have adjusted to but those from out of town are amazed with the fog.

“It’s kind of crazy. It was foggy over the lake and then it was really sunny over in the southern part a little bit,” said Lucas Bartlett, who was biking on the foggy day.

Bartlett was checking out area bike trails from southern Minnesota. Instead of a view of the blue waters of Lake Superior, his view Thursday became a sea of gray working its way through the city.

“Initially it was kind of like, ‘Oh it was foggy so it wasn’t as great’ it on a couple of the sections up higher, you were above the fog a little bit. Which was cool.”