What Affects my Air Quality?

Air quality where you live can vary depending on how much air pollution is emitted in your community, how much pollution is carried into your community on the wind, and by weather conditions.

Ozone forms when two key pollutants, nitrogen oxides (NOx) and volatile organic compounds (VOCs) “cook in the sun.” These pollutants are precursors to ozone formation, meaning they must be present in the air for ozone to form. Particle pollution can be directly emitted (like smoke from a woodstove), but a lot of particles form when gases react in the air. NOx and sulfur dioxides (SO2) contribute to particle formation.

These ozone and particle-forming pollutants come from a wide variety of sources, including mobile sources, power plants, and industries. Natural sources contribute, too: wildfires and volcanoes contribute to particle pollution, while trees and other vegetation can contribute both to particle and ozone pollution.

Weather plays a big role in the levels of ozone and particle pollution in your community. Sunlight and heat, for example, promote ozone formation. Light winds and temperature inversions both can keep pollution from dispersing. And depending on its direction, the wind can bring in more pollution – sometimes from hundreds of miles away. Geography can affect pollution levels too; mountain ranges, such as those in southern California, can prevent pollution from dispersing.

More about the elements of weather that affect air quality