The smoke is expected to remain over the northern and central Plains of the United States for the next couple of days, according to meteorologists.

If you have been experiencing itchy eyes or more sneezing on this Thursday it is likely caused by the thick haze over Denver and the entire state.

Last week, Canadian wildfire smoke blanketed Wisconsin and caused the Air Quality Index to reach the unhealthy level for sensitive groups. Six days later, on July 31, the smoke appears to have a worse impact on the air.