Air quality has been downgraded in the Rogue Valley until Thursday afternoon, as lingering temperature inversions will trap pollutants in the area, the National Weather Service reported.
NWS officials have issued an air stagnation advisory until 1 p.m. Thursday because of the inversions.
"It stays here, and anything in it stays here too," said NWS meteorologist Brian Nieuwenhuis.
The inversions are expected to start weakening Thursday afternoon. Air quality will then start to improve. Individuals with sensitive respiratory conditions like asthma should be cautious when doing physical activities outdoors until then.
The advisory extends from Ashland to as far north as Roseburg. Weather officials said this morning's freezing fog layer should burn off later today.
"The fog layer's pretty shallow," Niewenhuis said.
— Ryan Pfeil