Download our free iSmog app!

iSmog displays air quality information for the entire San Francisco Bay Area. Tap the screen to view an easy-to-understand map of environmental quality in the Bay Area’s five air basins, built using data provided by the Bay Area Air Quality Management District (BAAQMD). Use this app to make informed choices about environmentally friendly transportation options.

Use the app to:

  • Check the air quality before you bike or exercise
  • Get Spare the Air alerts
  • Learn about Bay Area air quality

Download for free at the iTunes App Store

iSmog uses push notifications

Customizable push notifications allow you to conveniently get customized air quality alerts anytime and anywhere, without even needing to load the app. The alerts will notify you about allergies and other environmental sensitivities when the air contains unhealthy levels of contaminants like ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and two sizes of particulate matter, all precursors of ozone. BAAQMD plans to continuously improve the information provided in the app so you can always expect updated information.

Additional features

Users can also get custom alerts to find out when Spare the Air days happen easily access the official Spare the Air Twitter feed at @sparetheair.

iSmog also includes useful information about how air quality scores are calculated, which can be used by local educators or nonprofits to discuss air pollution levels and issues unique to the Bay Area’s air basins.

Get more info

All Bay Area Counties (San Francisco, San Mateo, Santa Clara, Alameda, Contra Costa, Sonoma, Solano, Marin, and Napa) are covered by the iSmog app, but 511 Contra Costa provides additional support to commuters in Contra Costa County through our website. Air quality scores are made available publicly by the Bay Area Air Quality Management District (BAAQMD) at, and the app was designed by Blinktag, Inc., a small Bay Area planning firm dedicated to uniting the fields of technology, mapping, transportation, and urban planning.

Don’t have an iPhone? You can always view air quality forecast info directly on