Hermantown, Minnesota, experiences a humid continental climate characterized by warm summers and cold, snowy winters. The average annual temperature is approximately 39.6°F (4.2°C). During summer, temperatures typically range from highs around 79.9°F (26.6°C) to lows near 56.1°F (13.4°C). In winter, highs average 24.2°F (-4.3°C) with lows around 7.7°F (-13.5°C). The area receives an average annual precipitation of 31.5 inches (80 cm), with snowfall averaging 55.6 inches (141 cm). The wettest months are June, July, and August, while January tends to be the driest month.
Environmental stewardship has been a focal point in Hermantown. The Arrowhead Refinery site, a former oil recycling facility, underwent extensive cleanup efforts due to contamination concerns. In September 2021, the U.S. Environmental Protection Agency (EPA) removed the site from the Superfund National Priorities List, indicating that cleanup was complete and no further action was necessary beyond continued site inspections and land use restrictions.
More recently, the proposed development of a data center in Hermantown has sparked environmental discussions. Residents and environmental groups have raised concerns about the adequacy of the environmental review process. In March 2026, the Minnesota Pollution Control Agency (MPCA) released a study highlighting potential risks to native brook trout populations in the Midway River Watershed, which could be affected by the data center’s placement. The study emphasized the importance of protecting these habitats to maintain the health of local aquatic ecosystems.
Understanding Hermantown’s climate and environmental history is essential for residents and stakeholders to make informed decisions that balance development with ecological preservation.