### Unhealthy Air Quality Spreads Across Upper Midwest and North Central U.S. Due to Canadian Wildfire Smoke

The air quality in parts of the Upper Midwest and north central United States has deteriorated to dangerous levels as thick clouds of smoke from Canadian wildfires drift southward. Minnesota, western Wisconsin, eastern Nebraska, and the Upper Peninsula of Michigan have all been issued air quality alerts. Chicago may soon experience similar conditions as the smoke continues its southward journey.

According to the Nebraska Department of Health and Human Services, members of sensitive groups might experience severe health effects. When air quality reaches the "red" category, everyone is advised to limit prolonged or heavy outdoor activities. Individuals in sensitive groups are especially encouraged to stay indoors or reschedule outdoor activities.

Earlier this week, certain areas in Minnesota saw air quality indexes soar to over 200, landing in the "purple" category before improving later in the day to the "red" category. An air quality index above 100 is already considered unhealthy. The sky in many affected regions appears whitish or gray due to the smoke, sometimes altering the sun’s color to a peach hue. The presence of PM2.5 particulate matter in the smoke, hazardous when inhaled, is responsible for the degraded air quality. This fine particulate matter measures less than 2.5 microns in diameter, making it much smaller than the thickness of a human hair.

Minneapolis reported the second-worst air quality of any major city earlier this week, trailing only Kuwait City, which had an air quality index of 318. In contrast, Mohawk, Michigan, reached a staggering air quality index of 752, while Houghton, Michigan, hit an alarming 940.

The smoke originates from wildfires in northern Canada, particularly in Manitoba and Saskatchewan, which have already consumed around 4 million acres. The magnitude of these fires has forced over 17,000 residents to flee eastern Manitoba. The entire town of Flin Flon, located about 400 miles northwest of Winnipeg, was also evacuated due to the advancing flames.

Here's how the smoke conditions are affecting various cities:

- **Minneapolis:** Experiencing hazardous air quality Tuesday, with improvements expected by late Wednesday morning. Clearer conditions are predicted for Thursday, although there is a chance of the smoke returning later in the week.

- **Duluth, Minnesota:** Hazardous air quality was noted on Tuesday and early Wednesday. Conditions are forecasted to improve on Thursday before deteriorating again on Friday.

- **Kansas City area:** High-altitude smoky haze lingered on Tuesday, with hazardous concentrations expected on Wednesday and Thursday. Some residual smoke may persist on Friday.

- **Omaha:** Smoke increased through Tuesday afternoon, with partial relief anticipated on Wednesday. However, models indicate a denser plume could return on Thursday, potentially marking the week's worst air quality period.

- **Des Moines:** Moderate smoke levels were present on Tuesday, with a resurgence expected on Thursday. Southeastern Iowa may see continued smoke on Friday, while northern Iowa could see improvements.

- **Madison, Wisconsin:** Mostly clear skies on Tuesday, but hazardous air is likely on Wednesday and Thursday. Some improvement might come on Friday, but another substantial smoke plume could reach over the weekend.

- **Chicago:** Air quality remained acceptable until Wednesday into Thursday, when smoke may infiltrate, particularly in the northwest suburbs. Light to moderate smoke levels could persist for the rest of the week.

Additional cities such as Detroit, Marquette, Cleveland, Indianapolis, Memphis, Charleston, Atlanta, Savannah, Augusta, and Birmingham, Alabama, anticipate various levels of impact, primarily ranging from no significant changes to some high-altitude haze. Notably, Memphis experienced a morning haze of Saharan dust that dissipated by afternoon.

The situation underscores the vast impact of the ongoing wildfires and the need for affected residents to stay informed and take precautions to protect their health.