Climate Change Intensifies Duluth Heat Wave, Raises Heat Exhaustion Calls

Amid a sweltering heat wave, the impact of human-induced climate change has been thrust into the spotlight. Recent data from Climate Central’s Climate Shift Index reveals that the ongoing extreme temperatures in Duluth are significantly more likely due to today’s climate conditions, shaped by historical greenhouse gas emissions.

In areas along the Minnesota-Ontario border, where several wildfires are active, temperatures soared past 100 degrees on Monday. According to Climate Central, such extreme heat is now at least five times more prevalent than it would be without the influence of human-induced carbon emissions. In broader Northeastern Minnesota, the heatwave made temperatures two to four times more likely.

“This temperature would be very difficult to encounter in a world without climate change — not necessarily impossible, just highly unlikely,” Climate Central noted.

Minnesota State Climatology Office’s senior climatologist, Kenny Blumenfeld, highlighted the influence of rising global temperatures on the intensity and duration of heatwaves. “So it’s likely that the changing climate bears some of the responsibility for the scope of this heat episode,” Blumenfeld stated, adding that a detailed analysis is required to determine the precise extent of climate change’s role.

Blumenfeld also pointed out challenges in verifying the Climate Shift Index’s claims without examining the baselines used, noting that some weather stations do not include the 1930s—a period of notably high temperatures—in their datasets.

Wyatt Buckner / Duluth Media Group

Despite the discrepancies in historical data, Blumenfeld noted that northern Minnesota is warming more rapidly than the southern regions, with high-temperature records becoming more frequent in recent years.

Over the weekend, Duluth experienced temperatures in the 80s and 90s, prompting a rise in heat-related medical emergencies. Duluth Fire Chief Shawn Krizaj reported an increase in calls for heat exhaustion on Monday, with six incidents occurring between 10 a.m. and 2 p.m.

Prolonged heatwaves can exacerbate health issues, particularly when high temperatures persist overnight, Krizaj explained. “When you start getting that three, four, five days in a row, that’s when we start seeing increases,” he said.

Wyatt Buckner / Duluth Media Group

Local hospitals have reported varying increases in heat-related cases. While Aspirus-St. Luke’s emergency department noticed a rise on Monday, Essentia Health-St. Mary’s Hospital recorded seven cases over the weekend, consistent with past years. The heat has particularly affected vulnerable groups, including older adults and those in poorly ventilated apartments.

Duluth’s older housing and proximity to Lake Superior mean fewer homes have air conditioning, especially in areas with higher poverty rates and more elderly residents, according to a report earlier this year.

Residents sought refuge from the heat by swimming, spending time in air-conditioned spaces, and reducing outdoor activity. Some construction crews ended their shifts early to avoid the extreme temperatures.

Cory Rothstein, a National Weather Service meteorologist, forecasts that the intense heat will persist into Tuesday, with a possible dip in temperatures later in the week due to a “weak dry cold front.” Winds shifting from Lake Superior may offer cooler temperatures along the lakeshore later in the week, but the region will still experience above-normal temperatures.