Twin Cities air quality reaches unhealthy levels

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Twin Cities Air Quality Index (AQI) spikes this week. (Source MPCA)

Air quality has reached unhealthy levels in the Twin Cities and Rochester. As of Tuesday morning, the AQI in the Twin Cities is 131. In Rochester the AQI is 121. Readings over 101 are considered unhealthy for sensitive groups, such as those with respiratory problems like asthma. People in these groups are encouraged to minimize outdoor activity today. An air pollution health advisory remains in effect today.

A stagnant air mass has led to the higher levels of pollutants. November usually brings plenty of wind and fresh cold Canadian air masses to sweep away pollutants. A persistent patter of lighter winds this month has allowed fine particulate matter such as wood smoke particles and automobile exhaust to accumulate.

November is usually our 4th windiest month of the year in Minnesota. The average monthly wind speed for the Twin Cities in November is 10.9 mph. So far this month, the average wind speed in the metro is just 6.9 mph.

Northwest winds will increase Wednesday into Thanksgiving Day. That should sweep away the gunk and allow air quality to improve as we head into the Thanksgiving weekend.

PH