If you look at Oklahoma's air quality index, it reports that the air is good and moderate in some areas. Health experts say that's inaccurate, for the reason that it doesn't account for the particles that come from wildfires because they're too small.

Unusually vicious and damaging weather across multiple U.S. states spawned violent tornadoes, blinding dust storms, and fast-moving wildfires over the weekend, leaving at least 39 people dead.

A powerful storm system that tore across the United States in recent days is winding down Monday, but in its wake are devastated communities across states hit with violent tornadoes, wildfires and dust storms spun off by the massive system.