Smoke from Canadian wildfires spread deeper into Oklahoma on Thursday, resulting in an expanded listing of counties put under health advisories.
The initial advisory from the Oklahoma Department of Environmental Quality, issued Thursday morning included 17 counties near the state line with Kansas. However, by mid-afternoon, the advisory was widened to 32 counties and stretched as far south as the cities of Ardmore, Atoka and Duncan.
The air was considered to be unhealthy for sensitive groups, according to the Oklahoma Department of Environmental Quality.
To the north, Kansas City was under an alert.
Most of the remainder of the state was in what was considered to be moderate air in Oklahoma. Only three counties, McCurtain in the southeast and Texas and Cimarron in the Panhandle were listed as healthy air to breathe.