textproduct: Duluth

KEY MESSAGES

- Extreme Heat: Hot and muggy conditions today through Monday and possibly into Tuesday. Extreme Heat Warnings are in place through Monday areawide except Price County with a Heat Advisory.

- Fire Weather Conditions: Very little rainfall chances this forecast period. Ongoing heat and those dry conditions combine with gusty southwest winds and fairly low relative humidity to lead to fire weather concerns across northern Minnesota today and Monday, potentially Tuesday. Red Flag Warnings are in effect today and a Fire Weather Watch is in effect Monday.

UPDATE

Issued at 129 AM CDT Sun Jul 12 2026

Overnight convection remains well-north of the Borderlands early this morning as a few strong thunderstorms are ongoing in North of Superior in Ontario right now. The 15 to 30 percent chance of precipitation remains for an isolated high-based rain shower still breaking the cap aloft over the next few hours in the Arrowhead and later post-dawn along the South Shore.

Being well-under the warm sector at this point, ongoing overnight temperatures in the low to mid-70s are only forecast to drop a few more degrees into the sunrise hours Sunday morning. A quick warm up early this morning leads to forecast Heat Index values around 90 F by 10 AM this morning and only continuing to increase into this afternoon of course.

Most all Heat Headlines remain the same with the forecast this morning except an extension in time for the Price County Heat Advisory. That Advisory now ends Monday evening alongside the near- areawide Extreme Heat Warning covering all other Northland areas today and Monday.

Fire weather-wise today, there will be increasing southwesterly winds today gusting 20 to 25 mph and relative humidity is forecast to drop to 27-35% along and north of the Iron Range. These are all occurring in an area under Abnormally Dry to Severe Drought conditions that have seen little rainfall the last few weeks. Given the at-least Elevated to pockets of Critical Fire Weather conditions forecast today, with fuels guidance provided by Land Management partners, the previous Fire Weather Watch for Sunday afternoon and evening was upgraded this morning to a Red Flag Warning. This Warning only covers the Sunday afternoon and evening time period for the Iron Range northward.

For Monday fire weather conditions, there is even higher confidence in more widespread Critical Fire Weather conditions compared to today. This stems from a more well-mixed environment as stronger southwesterly winds move in overhead and mix down to 20-30 mph wind gusts Monday afternoon and evening. This setup favors slightly lower minRHs then Monday too for 22-35% along and north of US Hwy 2, but lowest in the Borderlands. The Fire Weather Watch for Monday afternoon and evening covering an area of northern Cass to southern Itasca to Carlton County and all areas northward remains in effect and has an even higher chance of seeing more traditional Critical Fire Weather conditions than those of today. The main story being that conditions are likely to be critical today for fire weather, and even more critical on Monday....potentially also Tuesday as these last few days of hot temperatures persist even under slightly lighter winds that day.

A weak and dry cool front moves across the Northland Tuesday from north to south and brings a decrease in dewpoints behind it. This will help to alleviate some of the HeatRisk by Tuesday PM for parts of northern Minnesota.

Future extensions in time of the ongoing heat Warning may be needed to also cover hot and muggy conditions that are likely still on Tuesday for the east-central MN and across most of northwest Wisconsin area. Other parts of the Northland, namely the Brainerd Lakes to Twin Ports area, may also see a need of some sort of Heat Headline into Tuesday daytime.

DISCUSSION

Issued at 204 PM CDT Sat Jul 11 2026

High pressure stretched from James Bay into the Central Plains early this afternoon with a trough analyzed across northwestern Minnesota from an area of low pressure in central North Dakota. A few isolated thunderstorms were seen on radar earlier across western Koochiching County. Temperatures will warm into the 80s and 90s across most of the Northland this afternoon with 70s and lower 80s along the North Shore. Mainly dry and humid conditions are expected to prevail through the afternoon. A few isolated showers and thunderstorms will be possible across the Borderlands this afternoon into this evening, but overall confidence on this is low with weak forcing in place. Convective temperatures will be in the upper 80s with CAPE around 2000-3000 J/kg in this area. With air temperatures rising into the upper 80s and lower 90s, this will likely be the mechanism for storms. Small hail and gusty winds will be the main threats with winds likely being driven by collapsing cores.

Heading into tonight, there are some hints for overnight convection in the northwest flow regime aloft. Weak forcing continues to be an issue and leads to lower confidence in the development of storms. Some CAMs hint at the development of showers and storms, but the 12z runs are less optimistic than the 00z runs. CAMs tend to struggle in weakly forced regimes, so the drier route seems more likely with a lack of a defined forcing mechanism.

Dangerous heat conditions are then expected for Sunday and Monday as temperatures reach into the 90s over most of the Northland with dewpoints in the 60s and 70s leading to hot and muggy conditions. With widespread Wet bulb globe temperatures in excess of 83F and Heat Risk in the Major category, the Extreme Heat Watch has been upgraded and expanded to an Extreme Heat Warning with this forecast package. Areas along the North Shore will likely not see much relief for the heat aside from locations immediately adjacent to Lake Superior. Have kept Price out of the warning for now due to lower forecast WBGTs and placed them in an Advisory, but they may need to be added for Monday. Little relief is expected for Sunday night into Monday with low in the upper 60s and 70s with continued muggy conditions.

Near-critical fire weather conditions will also be possible across the Boundary Waters into the Arrowhead Sunday and Monday as well. Southwesterly winds will gust to 20 to 25 mph in this area with dewpoints falling into the 25-30% range, especially on Monday. Fire Weather headlines may be needed with these conditions in place. There are low chances for isolated showers and storms each afternoon, but the hot temperatures will likely keep activity from developing with capping aloft. Should anything develop Sunday afternoon, storms may be strong to severe with wind gusts to 60 mph and hail up to ping pong ball size possible with sufficient shear to support supercells.

A cold front is expected to push from north to south across the region Tuesday into Tuesday night. This will likely be a dry frontal passage, but it will push the low-level moisture to our south. Highs Tuesday will again reach into the upper 80s and 90s with dewpoints in the 60s ahead of the front. Heat headlines may need to be extended into Tuesday. Temperatures cool slightly for Wednesday through Friday, especially near Lake Superior where the lake breeze is expected to push inland. Highs will be in the 80s and low 90s away from Lake Superior with 70s and lower 80s near the lake. Dewpoints will also be in the 50s to lower 60s during this time, so it will feel significantly less muggy. Northwest flow aloft will bring periodic waves through the Upper Midwest during this time and may lead to isolated showers and storms, but no large organized systems are expected.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 617 AM CDT Sun Jul 12 2026

VFR conditions prevail this TAF period. Southwest winds sustained around 10 knots gust 15-25 knots today, with mixing prevailing after sunset tonight for continued southwest winds 5-10 knots into Monday morning.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 126 AM CDT Sun Jul 12 2026

This will be a two day period of gusty southwest winds across parts of the western waters. Gusts to 25 knots today are most likely in far western Apostle Islands and offshore of Grand Portage. Small Craft Advisories were issued this morning for those general areas ending late this evening. Waves may linger around 3-4 feet tonight offshore of Grand Portage so there is a small chance of needing an extension in time of that Grand Marais to Grand Portage zone Advisory running through tonight and Monday evening. Another day of even stronger winds gusting to 30 knots is likely Monday and Advisories are expected to be needed in time for similar, if not even more widespread, nearshore zones into Monday night.

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

FIRE WEATHER

Issued at 119 AM CDT Sun Jul 12 2026

The hot temperatures set up today and last into Monday. There will be increasing southwesterly winds today gusting 20 to 25 mph and relative humidity is forecast to drop to 27-35% alond and north of the Iron Range. These are all occurring in an area under Abnormally Dry to Severe Drought conditions that have seen little rainfall the last few weeks. Given the at-least Elevated to pockets of Critical Fire Weather conditions forecast today, from fuels guidance provided by Land Management partners, the previous Fire Weather Watch for Sunday afternoon and evening was upgraded this morning to a Red Flag Warning. This Warning only covers the Sunday afternoon and evening time period for the Iron Range northward.

Southwesterly 20 foot winds tonight remain mixed out from 5-10 mph with recovery relative humidity of 60 to 80% for the Range to Borderlands in far northern Minnesota.

For Monday, there is even higher confidence in more widespread Critical Fire Weather conditions compared to today. This stems from a more well-mixed environment as stronger southwesterly winds move in overhead and mix down to 20-30 mph wind gusts Monday afternoon and evening. This setup favors slightly lower minRHs then Monday too for 22-35% along and north of US Hwy 2, but lowest in the Borderlands. The Fire Weather Watch for Monday afternoon and evening covering an area of northern Cass to southern Itasca to Carlton County and all areas northward remains in effect and has an even higher chance of seeing more traditional Critical Fire Weather conditions than those of today.

For Monday evening and early overnight, the southwest 20 ft winds are forecast to remain even more mixed out (20 foot sustained 7-10 mph and gusts still 15-20 mph) than those Sunday night. As a dry and weak cool front drops north to south in the pre-dawn hours Tuesday morning, those winds shift to westerly and decrease to become 5 to 10 mph. Recovery RHs Monday night trend slightly lower compared to Sunday night, but still remain 60-75% for the areas in the Fire Weather Watch.

While not very likely (85% chance of not occurring) a few strong thunderstorms cannot be ruled out in the Tip of the Arrowhead Sunday late afternoon and then into the South Shore and WI Rte 13 corridor by Sunday evening. The primary hazards would be small hail, gusty erratic winds to 50 mph and a brief heavy downpour if these storms do even form.

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

CLIMATE

Issued at 106 AM CDT Sun Jul 12 2026

Daily high temperatures and daily record warm low temperatures are forecast over the next few days at select Climate sites in the Northland. The current temperature record and year it was observed are in the first column, with the current forecast temperature in the second column.

Site Identifiers and Names KDLH: Duluth Area (measured at Duluth Int'l Airport) KINL: International Falls area (measured at Int'l Falls Airport) KHIB: Hibbing area (measured at Range Regional Airport) KBRD: Brainerd area (measured at Brainerd Regional Airport) KASX: Ashland area (measured at JFK Memorial Airport)

Record Daily High Temperatures:

July 12: Forecast KINL: 96/1921 99 KHIB: 91/1969 95

July 13: KINL: 93/1983 100 KHIB: 92/1983 96

July 14: KASX: 94/1980 94

Record Daily Warm Low Temperatures:

July 12: Forecast KDLH: 70/1892 68 KINL: 69/1898 70 KHIB: 67/1942 68 KASX: 67/2018 67

July 13: KINL: 69/2013 74 KBRD: 73/1936 71 KHIB: 67/1997 70 KASX: 73/1954 72

July 14: KDLH: 75/1983 72 KINL: 70/1983 71 KBRD: 72/1901 72 KHIB: 69/1995 70

DLH WATCHES/WARNINGS/ADVISORIES

MN...Extreme Heat Warning from 11 AM this morning to 1 AM CDT Tuesday for MNZ010>012-018>021-025-026-033>038. Fire Weather Watch from Monday morning through Monday evening for MNZ010>012-018>021-025-026-037. Red Flag Warning from noon today to 9 PM CDT this evening for MNZ010>012-018-019. WI...Extreme Heat Warning from 11 AM this morning to 1 AM CDT Tuesday for WIZ001>004-006>008. Heat Advisory from 11 AM this morning to 1 AM CDT Tuesday for WIZ009. MARINE...Small Craft Advisory from 10 AM this morning to 10 PM CDT this evening for LSZ140-146-147-150. Extreme Heat Warning from 11 AM this morning to 1 AM CDT Tuesday for LSZ142.