The air quality alert covering Bloomington and the rest of the Twin Cities expired at 6 p.m. Friday, July 17. By 11:30 that morning, Minneapolis had already dropped to 84th on IQAir's global ranking of major cities, a big fall from Thursday afternoon, when it had the worst air of any major city in the world. The metro got relief, but northern Minnesota's Arrowhead region stayed under a hazardous-level alert through 11 a.m. Monday.
Here's how it unfolded. The Minnesota Pollution Control Agency issued an alert as very heavy smoke from large wildfires in the Arrowhead and southern Canada pushed south. The alert grew to cover 8 regions of the state, including the metro, Duluth, Rochester, Brainerd, St. Cloud and Mankato. The Twin Cities landed in "maroon," the worst category. That rating is hazardous for everyone and comes with guidance to stay indoors and skip all outdoor activity. The agency said most people would notice irritated eyes, nose and throat, coughing, chest tightness or shortness of breath. Anyone with severe symptoms was told to call 911.
This was not an ordinary smoky summer day. The state climatology office called it the worst and most widespread smoke outbreak on record in Minnesota. A sensor in Blaine measured 342.8 micrograms per cubic meter of fine particulates, which broke the Twin Cities record by a large margin. A West Duluth sensor read 617.8, which appears to be the state's all-time hourly record. By July 16 the fires up north had burned more than 50,000 acres near the Boundary Waters, with little if any containment.
On Thursday, July 16, the smoke closed things down locally. The Bloomington Family Aquatic Center closed. In Richfield, the city canceled an evening building-materials swap. Edina closed its Aquatic Center. At Centennial Lakes Park, the farmers market went ahead from 3 to 7 p.m.
The heat made things worse. Health officials told people with heart or lung conditions, older adults, children and pregnant people to stay inside and keep activity low.
For the next 12 hours and today's records, see Bloomington weather; for the days ahead, the 10-day forecast.
