textproduct: Duluth

KEY MESSAGES

- Dangerous heat comes to an end this evening.

- Smoky conditions continue and will be in and out throughout the week.

- Two rounds of showers and storms are expected with cold fronts Friday and again Monday.

DISCUSSION

Issued at 249 PM CDT Wed Jul 15 2026

For the rest of the day, a stalled frontal boundary remains stretched across central Minnesota into northwest Wisconsin. Dewpoints are gradually dropping from north to south behind this boundary. Thick wildfire smoke advecting southwestward is keeping temperatures cooler than previously expected. Consequently, the Heat Advisory has been cancelled for several central areas, but a Heat Advisory remains in effect until 9 PM this evening along our southern tier of counties. With very dry air in place, near- critical fire weather is possible this afternoon and evening from the Iron Range northward. Tonight, skies will be mostly cloudy with smoke thickening, while a few isolated showers could clip the far northern borderlands after midnight.

On Thursday, wildfire smoke will continue to linger across the Northland due to persistent northwesterly flow and very poor atmospheric mixing. Highs will remain unseasonably warm in the 80s for most inland locations. However, a lake breeze developing over Lake Superior will keep coastal areas cooler, in the 70s and lower 80s. This onshore wind will also increase the risk of dangerous rip currents at Twin Ports beaches. Rain chances will slowly rise through the day, with scattered light showers and perhaps a few isolated, non-severe thunderstorms developing by Thursday afternoon, particularly across northern Minnesota and near the international border.

By Friday, a brief reprieve from the thickest smoke may occur as low-level winds shift to the southwest ahead of a cold front. This front is forecast to trigger widespread showers and thunderstorms starting late Thursday night and continuing through Friday. Rainfall of a quarter-inch to a half-inch is generally expected, with localized amounts up to an three quarters of an inch. While this rain is highly beneficial for the wildfires up north, the potential for lightning in the dry Arrowhead raises concerns for new wildfire starts. A few severe storms are possible in the Arrowhead and northwest Wisconsin as well, with damaging winds and large hail possible. High temperatures will vary widely on Friday, ranging from the humid upper 80s to cooler 70s along the North Shore within the lake breeze.

As the cold front exits to the east, dry and sunny conditions will return for Saturday. High temperatures will generally rise into the 80s. However, the post-frontal northwesterly flow will likely pull thick wildfire smoke back into the region. Places that get the thick smoke will likely have lower high temperatures than forecast. Sunday will start mostly sunny and warm, with highs once again reaching the 80s to near 90 degrees. A weak shortwave passing through could trigger a few isolated showers or storms by late Sunday afternoon, but most areas will remain dry.

A stronger weather system is forecast to cross the region Sunday night into Monday as an upper-level low tracks to our north. This system will bring another round of much-needed precipitation to the area. Once this system exits, dry and smoky conditions are expected to resume for much of next week. A cooler, more seasonal air mass will filter in behind this second front, bringing relief from the recent heat as daytime highs trend back into the comfortable 70s by Tuesday.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1240 PM CDT Wed Jul 15 2026

VFR conditions will be interrupted by smoke from the wildfires in the BWCA. Smoke will lead to MVFR/IFR visibilities. There will be a brief improvement for most, if not all, terminals this afternoon/evening, but is expected to return overnight. North to northeast winds will veer to the east throughout the TAF period and will largely remain below 10 kts.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 219 PM CDT Wed Jul 15 2026

A Dense Smoke Advisory remains in effect until 4 PM CDT Thursday for all nearshore and open waters of western Lake Superior, as thick wildfire smoke reduces visibilities to 1 to 5 nautical miles at times. Light winds of 5 to 15 knots will continue through Thursday morning, with waves generally under 2 feet. By Thursday afternoon, northeast winds are expected to increase in the southwestern arm of the lake, with gusts up to 25 knots and waves building to 3 feet in the Twin Ports, potentially leading to hazardous conditions for small craft. Showers and thunderstorms become likely late Thursday night into Friday as a cold front approaches.

For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt.

FIRE WEATHER

Issued at 219 PM CDT Wed Jul 15 2026

A Special Weather Statement has been issued for near-critical fire weather conditions this afternoon and evening across far northern Minnesota due to dry air, with minimum relative humidity values of 25 to 35 percent. Winds will remain light under 10 mph today. Humidity recoveries tonight will be good, reaching 75 to 85 percent. On Thursday, minimum relative humidity will range from 35 to 45 percent with light east winds. Rain chances increase with a cold front late Thursday night into Friday with a quarter-inch to a half-inch of rain expected, though lightning in the dry Arrowhead introduces the danger of new wildfire starts. Generally dry and warm weather returns this weekend, with another cold front bringing showers and storms on Monday followed by a cooling trend and northwest winds by Tuesday.

See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions.

DLH WATCHES/WARNINGS/ADVISORIES

MN...Heat Advisory until 9 PM CDT this evening for MNZ033-034-036- 038. WI...Heat Advisory until 9 PM CDT this evening for WIZ006>009. MARINE...Dense Smoke Advisory until 4 PM CDT Thursday for LSZ121- 140>148-150.