textproduct: Duluth

KEY MESSAGES

- Cooler today with lingering morning showers. Breezy northerly to northwesterly winds will lead to near-critical fire weather conditions in northeastern Minnesota.

- Drier with more seasonable temperatures on Wednesday, gradually warming up again towards next weekend.

UPDATE

Issued at 1250 AM CDT Tue Jul 21 2026

A secondary cold front stretched from an area of low pressure north of Lake Superior back to the southwest across northeastern and central Minnesota and into northern South Dakota. A few isolated showers and thunderstorms will observed on radar with the heaviest activity across northern Ashland and Iron counties. Showers and perhaps a few rumbles of thunder will linger in spots through mid to late morning before drier air starts to work in and bring an end to this activity. Skies will gradually clear through the afternoon with mainly clear skies tonight. Northerly to northwesterly winds will remain breezy into this afternoon with gusts to 20 to 30 mph possible before quickly diminishing late this afternoon as high pressure begins to work in. Today will be the coolest day in weeks with highs in the 70s. A general warming trend is then expected through the remainder of the week and into the weekend with hot conditions returning next weekend. No significant changes to the extended portion of the forecast with this update.

DISCUSSION

Issued at 117 PM CDT Mon Jul 20 2026

A pattern change with cooler and drier air across the Northland mid- week, then a return to warmer temperatures late week into next weekend. Occasional chances for precipitation, but no significant precipitation amounts nor signal for severe storms through the next 5-7 days, with long-range outlooks heavily favored toward above normal temperatures through the end of July.

A secondary cold front moves north to south tonight through the region bringing low level moisture along the front and cooler and drier air in its wake through mid-week as high pressure builds in with north-northwesterly flow aloft. The airmass aloft is so cool with 850mb temps of +2-6C it is actually below the tenth percentile of climatology for the International Falls RAOB climatology for this time of year.

Tonight the final cold front moves north to south bringing with it low level moisture/clouds and then drier air in its wake. This will lead to cloud cover overnight into Tuesday with light rain showers (or perhaps even more like drizzle/sprinkles towards Tuesday morning) but overall little in the way of measurable precipitation.

With the cooler airmass tomorrow highs will range from the mid 60s in the MN Arrowhead to the 70s elsewhere, with the Duluth forecast of 72 at the airport being the coolest day of July (coolest since 71 on June 29) - and it'll even be 66 near the lake! Gradually warming up through mid week as an area of high pressure builds in.

Late-week there will be a broad upper level ridge over the western CONUS and a deep-level trough over eastern Canada and the northeast leading to northwesterly flow aloft for the Upper Midwest. In this northwesterly flow there will be a few weak mid-level impulses with increasing low level temps in the westerly flow at low levels. This will lead to a few chances for precipitation late week into next weekend. Timing is tough to nail down due to the range in guidance, but generally most scenarios look to be light/limited precip and no strong signal for organized severe storms. Precipitation amounts at best are likely less than quarter inch over the weekend (70-85% of ensemble guidance). Highs back into the upper 80s and low 90s Saturday and Sunday, and Heat Advisories will likely needed for parts of the Northland.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 623 AM CDT Tue Jul 21 2026

The main forecast challenge this morning is timing out when MVFR ceilings may mix out later this morning. We have plenty of low clouds, but also patches of clearing with this northerly flow. I went with my best analysis of model trends and current satellite views of cloud coverage to time out ceilings mixing to VFR. I would expect that times could be off by an hour or two. Stray showers could affect DLH/HYR for a couple hours this morning. Gusty winds are expected through the day, then decreasing pretty quickly and becoming light around sunset. VFR conditions are expected this afternoon and through the rest of the period with high pressure moving in going into Wednesday.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1250 AM CDT Tue Jul 21 2026

Gusty westerly winds will turn more northwesterly through the early morning hours in the wake of a cold front. These northwesterly winds will persist through the day at 10 to 15 knots with gusts to 20 to 30 knots, highest along the North Shore. Small Craft Advisories have been extended into this afternoon due to these gusty winds. High pressure quickly builds in this evening with winds diminishing to 5 to 15 knots out of the northwest. Southwesterly winds are then expected for Wednesday through Friday and into the weekend at 5 to 15 knots.

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

FIRE WEATHER

Issued at 1250 AM CDT Tue Jul 21 2026

A few showers may linger this morning with skies gradually clearing through the day. Afternoon RH values will fall into the 40 to 50% range. Winds will remain breezy into the afternoon with northerly winds gusting to 20 to 30 mph before quickly diminishing by early evening. Highs will be much cooler in the 70s. High pressure then settles in for Wednesday and Thursday with mainly sunny and dry conditions. Highs will warm back into the 80s with afternoon RH values in the 30 to 40% range. No significant rain chances are expected through the end of the week. Temperatures warm back into the 80s and 90s for the weekend with breezy conditions possible on Saturday.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Small Craft Advisory until 4 PM CDT this afternoon for LSZ121- 140>148-150.