Air quality conditions began to decline in the region Tuesday, the day after the Ross fire started about 100 miles west of Dallas, according to the weather service. The smoke, which is thicker than a typical fog, prompted Fort Worth ISD to cancel all outdoor activities Wednesday.

Monique Sellers, a meteorologist with the weather service, said other wildfires in the region have also worsened the air quality. North Texans will likely not get a reprieve until the fires are contained, but until then, “we’re going to be in this holding pattern,” Sellers said. According to estimates from the Texas A&M Forest Service Thursday, the Ross fire stood at about 85,000 acres and was about 21% contained. 

The Texas Commission on Environmental Quality forecast the air quality would be “unhealthy for sensitive groups” from Thursday to Saturday in Dallas-Fort Worth. The designation generally means members of sensitive groups, those with asthma or other health conditions, may experience some impacts on their health, but the general public is less likely to notice any effects. Sellers advised that those with sensitivities stay indoors. 

The Dallas Morning News is separately tracking the air quality in the region through a map that updates every 10 minutes.