Idaho — A dull gray sky presses low over the Treasure Valley this morning, and the air feels heavy before the day even gets moving. Calm winds and trapped cold air are setting the stage for worsening air quality across southwest Idaho.
According to the National Weather Service in Boise, an Air Stagnation Advisory remains in effect through late Thursday morning. A strong temperature inversion has settled near the surface, preventing pollutants from dispersing. Light winds and limited mixing allow exhaust, wood smoke, and other emissions to linger, especially in valley locations.
Boise, Nampa, Meridian, and Caldwell are all affected, along with nearby rural communities. Morning fog adds to the issue, reducing visibility and reinforcing the stagnant air mass. Commuters may notice hazy conditions along I-84 and local surface roads, particularly during early travel hours.
Daytime temperatures climb into the low 30s this afternoon, but the warming is shallow. Cold air remains trapped near the ground, keeping the inversion intact. Patchy fog redevelops tonight and lingers into Tuesday morning, prolonging poor air quality conditions.
Health impacts are the primary concern. People with asthma, heart disease, or other respiratory issues may experience increased symptoms. Officials recommend limiting outdoor activity, avoiding unnecessary driving, and reducing wood-burning if possible. Even healthy individuals may notice throat or eye irritation during prolonged exposure.
Conditions slowly improve by midweek. Sunshine increases Wednesday, and highs rise into the mid-30s. By Thursday, temperatures push closer to the upper 30s, which may finally weaken the inversion. Until then, air quality concerns remain elevated.
Looking ahead, long-range outlooks suggest a gradual warming trend into late January, improving dispersion conditions across the Treasure Valley.
Do you notice the haze or fog lingering longer than usual where you live? Share what the air looks like in your neighborhood.
Five-Day Outlook for Boise, ID
Today: Patchy fog, mostly cloudy, high near 32
Tuesday: Morning fog, mostly cloudy, high near 32
Wednesday: Mostly sunny, high near 34
Thursday: Partly sunny, high near 37
Friday: Mostly sunny, improving air quality, high near 44
