As the extreme heat and humidity of the last few days comes to an end this evening, that will be replaced with unhealthy air becoming the issue. A cold front moving through the state tonight will lead to lower dew points, but it will also allow a thick haze of smoke over Minnesota to drift south into Iowa tonight. This will lead to poor air quality that could make it difficult to breathe for people in more sensitive groups.
Here is a look at where the worst of the air was sitting as of Thursday night. It is bottled up in Minnesota.
As the cold front drops south, the smoke will start to move south into Iowa. By midnight, it will make it to the I-80 line and to the Missouri border by early Friday. The smoke will stay heavy over our skies through the day on Friday, until afternoon.
The fine particulate matter in the atmosphere will have the most impact on those with breathing sensitivities, heart and lung conditions, the elderly & young children. Limit time outdoors and avoid strenuous activities during the time.