Fog, 81°F Heat, Then a 20-Degree Drop — Duluth's Wild Weather Week Explained

Dense fog gripped the Twin Ports waterfront Monday morning, but that’s just the beginning — a dramatic temperature swing and breezy Wednesday winds are already on the way.

If you’re in Duluth right now and wondering why visibility near the harbor dropped to about a quarter mile this morning — you’re not imagining it. A Dense Fog Advisory from the National Weather Service kept conditions murky along the waterfront and near bridges on I-35 and Highway 61 through 10 a.m., with damp pavement making the commute slower than usual.

The fog is already lifting as southwest winds pick up through the afternoon. Temperatures are climbing toward 70°F, and a brief shower or two could pop up near midday before skies start to brighten heading into the evening. The broader picture for northern Minnesota today: quieter and gradually improving.

From chilly 40s at dawn to near 81°F by Tuesday afternoon — that’s one of the sharpest two-day temperature swings Duluth has seen this spring.

Tuesday is shaping up to be the week’s highlight. Sunny skies and temperatures approaching 81°F will make it one of the better outdoor days in recent memory — though residents close to Lake Superior’s shoreline will likely feel a noticeable cool difference compared to inland spots. If you’re planning anything outside, Tuesday is your window.

Then comes Wednesday’s reality check. East winds return, knocking temperatures back into the lower 60s near the lake. The National Weather Service notes gusts around 25 mph along the Duluth waterfront, enough to make it feel noticeably cooler after the warmth of Tuesday. Inland areas will stay milder, but the shoreline will feel the contrast sharply.

The bigger regional story is a warming trend across the Upper Midwest that’s gradually pulling heat northward. Long-range forecasts are already signaling above-normal temperatures across much of Minnesota heading into early June — so while this week has its up-and-down moments, the overall trend is toward a warmer start to summer.