A long-duration heat wave affected Minnesota from Saturday July 11 through Monday July 20, with widespread temperatures in the 90s F across virtually all of the state for at least part of the time.
After a rather stormy period from late June into early July, a large ridge of high pressure settled over the central U.S., setting up a classic "heat dome" to its west and north, affecting the Great Plains and Upper-Midwest, including Minnesota.
Hot weather built into the region on Saturday July 11, beginning in the north, with temperatures climbing into the low to mid-90s F. Temperatures were largely in the mid 80s to around 90 F in the south. This "geographically-inverted" pattern, with the north warmer than the south, is common when Minnesota is north and northwest of the summer high pressure ridge, and dominated the first few days of this heat wave. By Sunday, temperatures had reached the up 90s F at locations near the Canadian border, with low upper 80s and 90s over much of the rest of the state. International Falls broke a daily high temperature record, with a high of 98 F. Duluth and St. Cloud reached 91 F, and the Twin Cities reached 90 F.
The pattern replayed itself on Monday, but during Tuesday the heat remained or intensified slightly over the central and south, but some of the extremes were shaved off of far northern Minnesota, as cooler air trudged into the region from Canada. Temperatures reached 94 F in the Twin Cities, 93 F at Duluth and St. Cloud, 91 F at International Falls, and 90 F at Rochester.
On Wednesday, the heat abated substantially over central and northern Minnesota, thanks to both a cool front, and, unfortunately, a severe wildfire smoke outbreak from fires in the Boundary Waters. Stations in the southern half of the state remained hot, with 96 F in the Twin Cities, 92 F in Rochester, and 91 F in St. Cloud. Parts of northern Minnesota remained in the 70s F, but this was not a pleasant cool-down. The wildfire smoke was so thick that it prevented full sunlight from reaching the ground, dropping temperatures significantly.
The highest temperature recorded officially during this heat wave (July 11-20) was 100 F at Kettle Falls, which is on the Canadian border near Rainy Lake.
This was a prolonged period of hot weather, creating some exposure hazards for Minnesotans, but over most of the state it was not particularly unusual. The heat was not uniquely intense. In fact, most areas saw lower maximum temperatures and Heat Index values than would typically be found on the hottest and/or most humid day of the year. The one exception was in far northern areas, where heat intensity during Sunday and Monday (July 12th and 13th) was about as high as could be expected in most years.
This was a somewhat long heat wave, especially in the Twin Cities, where the urban environment boosts temperatures several degrees above surrounding areas. The Twin Cities had 10 days in a row with high temperature of T least 90 degrees F, which was the third longest such streak on record, behind 14 days in 1936 (during an incomprehensible heat wave -- see note below). The Twin Cities also had 10 consecutive days with low temperatures of at least 70 degrees F, which is tied with 1941 for second longest on record, behind the record of 11 days set in 1935.
A note on records: Although International Falls broke daily temperature records with 98 F on the 12th and 97 F on the 13th, virtually no other historical station in Minnesota did the same. The reason? International Falls was not recording temperatures during the extraordinary July 1936 heatwave, which is the longest and most severe run of high temperatures on record for Minnesota. During that scorching and deadly period, nearby stations at Littlefork and Big Falls exceeded 100 F five or six times and reached as high as 106 F! Other stations along the Canadian border also exceeded 100 F multiple times, and it is exceedingly likely that International Falls would have too, if it had been taking observations.
Updated July 24, 2026
KAB & PJB