With an intense warm front setting record temperatures Friday, no immediate relief is in sight, and the Northland will likely continue to sweat it out again Saturday.
As of 5 p.m. Friday, the temperature at Duluth International Airport had climbed to 93 degrees, breaking the previous record high for June 4 by 3 degrees, according to the National Weather Service.
For much of the day, there was a sharp differential in temperature from the lakeside to the upper reaches of Duluth. But temperatures at Duluth's waterfront shot up dramatically with a shift in the wind late Friday afternoon. The temperature at Sky Harbor Airport read 68 degrees at 4:35 p.m. and 93 degrees at 4:55 p.m., a spike of 25 degrees in just 20 minutes.
The rapid temperature escalation accompanied a change in wind direction, with a light northeast breeze being replaced with a light southwest wind, noted Ketzel Levens, a meteorologist for the National Weather Service station in Duluth.
"We also noticed the relative humidity plummeted. So, this really warm air mass that's been over the land most of the day is a very dry one, and that finally caught up to Sky Harbor," she said. The relative humidity there dropped from 78% to 24% as the warm air swooped in.
"It was wild," Levens said.
International Falls stood out as the regional hotspot, however, reaching 98 degrees shortly before 3 p.m. The previous record temp for the city was 92 degrees.
The temperature at the Chisholm-Hibbing Airport reached 94 degrees shortly before 5 p.m., shattering the previous high for the day of 88 degrees.
Such high temperatures in early June are particularly unusual, Levens observed. She noted that the last time Duluth recorded a 90 degree June temperature was in 2005.
"Tomorrow, we've got another hot day rolling in," Levens said. She said temperatures for Saturday are likely to be as warm, if not warmer, than they were today, with increased humidity possibly adding to the discomfort.
"We're going to stay under this southerly flow," Levens said, with continued strong south-to-southwest winds bringing more warm air into the region.
She said storm systems are likely to develop Saturday and Sunday evening.
Lake Superior's surface-water temperatures are climbing, too, into the 55- to 57-degree range. But Levens said strong southerly winds could push that warming water away from shore, bringing up colder water from below.
Some of the pending storms this weekend could be severe, Levens said.
"We've got plenty of fuel out there for them with this heat, and then increased humidity coming in tomorrow," she said.
Saturday evening's storm is shaping up to be most intense up north, affecting border communities and the Iron Range, with Duluth likely on the periphery, Levens said.
But Sunday's storm system will likely encompass the whole of Northeastern Minnesota and Northwestern Wisconsin, she said.
"There's definitely the potential for some more severe storms," Levens said.