Air quality alert extended for parts of Minnesota

Our latest air quality alert for Minnesota has been extended until 11 p.m. for most of southwestern Minnesota.

A plume of smoke has been drifting across the Upper Midwest again this week. The thickest smoke layers have been across the Dakotas and western Minnesota.

Air quality readings Wednesday afternoon still show unhealthy levels of fine particulate matter (smoke) across southwestern Minnesota. Air quality readings in the city of Marshall have been in the 140s on Wednesday.

There is still a milky white-tinted sky across our state Wednesday from smoke aloft, but air quality is good at ground level in most of the Twin Cities area and eastern Minnesota.

Here is the language on the latest alert from the Minnesota Pollution Control Agency:

The Minnesota Pollution Control Agency (MPCA) has extended the air quality alert for southwest Minn. The alert now runs until 11 p.m. on Wednesday, Aug. 30. The affected area includes Marshall, Worthington, and the tribal nation of Upper Sioux.

Calm winds have allowed heavy ground-level smoke to linger over southwest Minn. this morning. Winds will remain light until the early afternoon, and fine particle levels may remain high throughout the day. Winds will become stronger from the southeast in the afternoon and air quality will improve across southwest Minn. on Wednesday afternoon. Fine particle levels should drop below alert levels by the end of the day.

Fine particle levels are expected to reach the orange air quality index (AQI) category, a level considered unhealthy for sensitive groups, across southwest Minn. In the orange area, sensitive groups should limit prolonged or heavy exertion and time spent outdoors.

Air quality will improve across Minnesota Thursday.

Here’s the latest forecast discussion from MPCA:

Updated Wed, Aug 30, 2023

The air quality alert has been extended for southwest Minnesota until 11 PM. The alert area over northwest MN has been allowed to expire. Calm winds have allowed heavy ground-level smoke to linger over southwest Minnesota this morning. Winds will remain light until the early afternoon, and fine particle levels may remain high throughout the day. Winds will become stronger from the southeast in the afternoon and air quality will improve across southwest Minn. this afternoon. Fine particle levels should drop below alert levels by the end of the day. Moderate smoke will linger across west central and northwest MN today and Yellow (moderate) AQI is expected there. Air quality across eastern MN will start off good, however smoke may mix to the ground during the afternoon across east central and southeast MN. This will produce air quality in the Yellow category for this region.