Air Quality
Air Stagnation Advisory Explained: Why Pollution Gets Trapped
What an air stagnation advisory means, how weather traps pollution, and why inversions can worsen smoke, haze, and winter air quality.
Quick answer: An air stagnation advisory means light winds and stable air may allow pollution, smoke, or haze to build near the surface.
The weather setup
High pressure, light winds, and inversions can limit vertical mixing. Pollutants then linger instead of dispersing.
Valleys are especially prone to trapped air during stable patterns.
Health impacts
People with asthma, heart disease, lung disease, older adults, children, and outdoor workers may notice symptoms sooner.
Air quality can change during the day as mixing improves or weakens.
What helps
Limit unnecessary burning, reduce vehicle idling, check AQI, and use cleaner indoor air when conditions are poor.
A front or stronger wind often helps clear stagnant air.