Poor Air Quality Expected as Air Stagnation Advisory Takes Effect in Southern Oregon

MEDFORD, Ore. (Dec. 28, 2025) — The National Weather Service has issued an Air Stagnation Advisory for several valley areas in southern Oregon, warning that poor air quality is expected to develop later today and persist through Wednesday afternoon.

The advisory is in effect from 4 p.m. this afternoon until 4 p.m. Wednesday. Forecasters say a temperature inversion combined with stagnant air conditions near the surface will trap pollutants, leading to deteriorating air quality across the region.

The advisory includes valley locations west of the Cascade Range in Jackson, Josephine and Douglas counties, as well as areas east of the Cascades in Klamath and Lake counties.

Poor air quality can pose health concerns, particularly for people with respiratory conditions. The National Weather Service cautioned that those with asthma, chronic obstructive pulmonary disease and other breathing-related illnesses may experience increased symptoms during the advisory period.

Health officials recommend that individuals with respiratory illnesses follow their physician’s guidance when air pollution levels are elevated. Limiting prolonged outdoor activity and avoiding additional sources of pollution, such as wood burning, may help reduce exposure during periods of stagnant air.

The advisory was issued by the National Weather Service office in Medford.