textproduct: Duluth

KEY MESSAGES

- Dangerous swimming conditions and hazardous boating conditions are expected this afternoon into the evening for the Twin Ports due to gusty northeast winds and building waves.

- Sensitive vegetation may be harmed tonight as a Frost Advisory has been issued for temperatures dropping to near freezing.

- Near-critical fire weather conditions are possible across the Northland today and Friday due to dry air and breezy winds.

- Widespread rain showers move in late Friday into Saturday, followed by a significant warming trend with well above normal temperatures arriving for Memorial Day and early next week.

DISCUSSION

Issued at 1221 PM CDT Thu May 21 2026

High pressure over the region today, providing mostly sunny skies and dry conditions across the Northland. High temperatures will reach the 60s for most inland locations, while a localized lake breeze keeps areas along the North Shore and the Twin Ports cooler in the 50s. Southerly winds will become breezy by the afternoon, dropping relative humidity values and creating near-critical fire weather conditions. As the evening approaches, a strong lake breeze will shift winds to the northeast around the head of Lake Superior, creating hazardous conditions for small craft and dangerous swimming conditions at area beaches. Overnight lows will drop into the mid 30s to lower 40s posing a risk to sensitive plants.

By Friday, the high pressure system will shift east over the Great Lakes, establishing a warmer southerly return flow. Expect another dry and breezy day with widespread highs in the 60s inland and cooler 50s near the lake. Fire weather conditions will remain a concern during the afternoon before moisture gradually begins to increase ahead of our next weather maker. Cloud cover will thicken late in the day as a low pressure system approaches from the Central Plains.

Rain showers are expected to spread across the area Friday and persist through Saturday morning as the system passes. This will bring a little rain to the region - on the order of a quarter to a half of an inch, but unfortunately this is it for most of the forecast period. High temperatures on Saturday will be somewhat cooler due to the clouds and precipitation, with most areas remaining in the 50s to 60s.

The extended forecast for Sunday through the middle of next week features a sharp transition to summer-like conditions. An upper level ridge will begin to build into the Upper Midwest on Sunday, allowing skies to clear and temperatures to warm into the 70s. By Memorial Day and continuing into Tuesday and Wednesday, hot and mostly sunny weather will dominate the Northland. Highs will soar into the 80s across the entire region, though still cooler by the lake, running well above normal for late May. While the pattern looks largely dry, northwest flow aloft could spark a few isolated afternoon or evening showers and thunderstorms if shortwaves align with instability.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 642 PM CDT Thu May 21 2026

VFR conditions will prevail for much of the period. Gusty winds this evening will diminish overnight before picking up again after sunrise Friday morning with gusts to 20 to 25 knots during the afternoon. Showers will move into the BRD area during the mid to late afternoon and bring MVFR to IFR ceilings and MVFR visibilities. Not expecting much in terms of thunderstorms with this activity.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1221 PM CDT Thu May 21 2026

Quiet conditions for now though expect building northeast winds at 10 to 20 knots with gusts up to 25 knots this afternoon for the Twin Ports area. A Small Craft Advisory is in effect as waves build to 2 to 4 feet. East to northeast winds will remain elevated on Friday at 15 to 20 knots with gusts approaching 25 knots, likely requiring additional advisories. Rain showers will move over the waters Friday night into Saturday, maintaining breezy easterly winds before conditions begin to settle by late Saturday night.

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

FIRE WEATHER

Issued at 1221 PM CDT Thu May 21 2026

Near-critical fire weather conditions are expected across the region today and Friday. Southerly winds will increase to 10 to 15 mph today with afternoon relative humidity values falling into the 25 to 35 percent range. A lake breeze off Lake Superior this afternoon will cause a wind direction change for coastal areas. Friday will feature similar humidity levels between 25 and 35 percent alongside east to southeast winds gusting up to 20 mph. Moisture and humidity recovery will begin Friday evening as a rain system approaches. Looking like more hot and dry conditions next week though not as much wind.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Frost Advisory from midnight tonight to 7 AM CDT Friday for MNZ012-019>021-037. Beach Hazards Statement until 10 PM CDT this evening for MNZ037. WI...Frost Advisory from midnight tonight to 7 AM CDT Friday for WIZ001. Beach Hazards Statement until 10 PM CDT this evening for WIZ001. MARINE...Small Craft Advisory until 10 PM CDT this evening for LSZ144- 145.