San Jose, the largest city in Northern California and the Bay Area with nearly 970,000 residents, is a highly diverse community. The city is located in Santa Clara County within the Bay Area Air Quality Management District (BAAQMD).

In recent years, San Jose and the broader South Bay have experienced a dramatic rise in unhealthy air quality days, with ozone and particulate matter (PM2.5 and PM10) being persistent concerns. Pollution is driven by heavy traffic congestion, industrial activity, and regional wildfire smoke, with low-income communities and communities of color-especially in East San Jose-bearing the brunt of exposure due to their proximity to highways and industrial areas. These conditions have led to higher rates of asthma and respiratory illness, and Santa Clara County consistently receives failing grades for ozone and particle pollution.

The district has teamed up with Aclima and the California Air Resources Board (CARB) to launch a community air monitoring project guiding future actions as a part of SMMI. Using Aclima’s advanced sensors, the project collects detailed, block-by-block data on air quality throughout the community. This provides residents with clear information about local pollution and helps guide actions to improve air quality, focusing on the areas and people most affected.

In April of 2025, San Jose residents and stakeholders met to discuss these pressing air quality challenges and explore solutions for a healthier, more equitable future.