Air Quality in Fontana, California — Live

Live readings from PurpleAir sensors across Fontana — with free alerts the moment the air turns.

Live Fontana AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Fontana and Rialto, Rancho Cucamonga, Bloomington, Colton.

Fontana was built around a steel mill. Henry J. Kaiser put it up in 1942 to feed his wartime shipyards, it was the largest integrated steelmaking plant on the West Coast, and it ran until December 1983. What replaced it was freight. Fontana now sits where Interstate 10, Interstate 15 and the 210 cross, and warehouses are concentrated heavily along the Slover Avenue corridor at the south end of town. That matters for the air in a specific, measurable way: heavy-duty diesel trucks are the main reason warehouse neighborhoods read higher for fine particles than the ZIP codes around them.

Canairy watches the sensors around your home, your kids' school, and everywhere else you care about, and tells you in plain English when the air changes enough to matter.

South Fontana sued over a warehouse, and won

In 2021 the California Attorney General sued the City of Fontana over its approval of the Slover and Oleander project, a 205,000-square-foot warehouse in south Fontana bordering Jurupa Hills High School. The settlement announced in April 2022 described the area as carrying some of the highest pollution levels in all of California, and said warehouse development in the city had gone unchecked for five years.

The outcome was Fontana's Industrial Commerce Center Sustainability Standards Ordinance, which the Attorney General's office called the most stringent warehouse standards in the state. New industrial projects have to route truck traffic away from schools, hospitals and daycares, install solar covering all of a larger building's energy needs, use zero-emission forklifts and yard trucks on site, and put in landscaped buffers. The developer also funded landscaping at Jurupa Hills High School and a five-year supply of air filters for roughly 1,750 nearby households. It applies to future projects, not to the warehouses already standing.

What the research says about living near warehouses

This is not a vague worry. A NASA-funded study published in the journal GeoHealth in October 2024 looked at about 11,000 warehouses across Los Angeles, Riverside, San Bernardino and Orange counties — a region that handles 40 percent of all US cargo containers — and found that ZIP codes in the top quartile for warehouse floor space carried 0.16 micrograms per cubic meter more PM2.5, with top-quartile truck parking adding 0.21. During peak holiday shipping the gap widened to roughly 4 micrograms. A companion national study of 150,000 warehouses found nitrogen dioxide running about 20 percent higher near warehouse sites.

Regulators have responded on two tracks. California's siting guidance advises against putting housing within 1,000 feet of an industrial warehouse because of truck traffic, and the regional air district's warehouse rule requires buildings of 100,000 square feet or more to earn credit for emission-reducing actions — cleaner trucks, on-site charging, air filtration — or pay a mitigation fee. Neither of those makes the air on Slover Avenue the same as the air up in Sierra Lakes, which is the practical reason to watch a sensor near your own address rather than a citywide number.

The mill is still there, and so is the ozone

Part of the original Kaiser plant still runs as California Steel Industries, and Auto Club Speedway went up on another piece of the site. Airborne emissions at the mill were already a public argument by 1970 — Fontana has been arguing about its own air for over half a century.

Layered on top of the local sources is the regional problem nobody here controls. Fontana sits at the downwind end of the basin, where the sea breeze deposits Los Angeles-area emissions after sunlight has cooked them into ozone. San Bernardino County ranked first in the nation for ozone in the American Lung Association's 2026 report, with 159.2 weighted unhealthy days a year.

Fontana air quality FAQ

Why is there smoke in Fontana today?

Fontana itself does not usually burn, but it sits downwind and downslope of country that does. The Cajon Pass is just northeast, and when the Blue Cut Fire burned roughly 37,000 acres there in August 2016 the smoke advisory named the northwest San Bernardino Valley. Fires in the San Bernardino National Forest, like the Line Fire near Highland in September 2024, put smoke into the same valley. Smoke can also arrive from the west. And in summer, a brown afternoon sky is often ozone rather than smoke.

What is the air quality in Fontana right now?

This page shows the current AQI for Fontana, calculated from PurpleAir sensors across the city and updated continuously. That distinction matters more here than in most cities, because the south end near the Slover Avenue warehouse corridor and the north end up toward Sierra Lakes can read differently on the same afternoon. The map below shows every live sensor.

Is it worse to live near the warehouses in south Fontana?

Measured air quality does differ near heavy warehouse and truck activity. Peer-reviewed work published in GeoHealth in 2024 found meaningfully higher PM2.5 in the Inland Empire ZIP codes with the most warehouse floor space and truck parking, and a national study found nitrogen dioxide about 20 percent higher near warehouses. The California Attorney General's 2022 settlement with the city specifically described south Fontana as carrying some of the highest pollution levels in California.

What did the Fontana warehouse ordinance actually change?

After the state sued over the Slover and Oleander project next to Jurupa Hills High School, Fontana adopted the Industrial Commerce Center Sustainability Standards Ordinance in April 2022. New industrial projects must keep truck routes away from schools, hospitals and daycares, put solar on larger buildings sufficient to cover their energy needs, use zero-emission forklifts and yard trucks, and install landscaped buffers. It governs future projects, not the warehouses already built.

What AQI level is unhealthy?

Under the US EPA scale, AQI 0–50 is Good and 51–100 is Moderate. From 101 the air is Unhealthy for Sensitive Groups — kids, older adults, and people with asthma or heart conditions — and above 150 it's Unhealthy for everyone. Canairy translates these numbers into a plain-English verdict, like whether to close the windows or move a workout indoors.

Is Canairy free?

Yes. The Canairy app is free to download and includes live air quality for all your saved places, plain-English verdicts, and free push alerts when the air crosses your threshold. A paid plan adds extras like SMS text alerts.

Get Canairy free on Google Play.