Air Quality in Stockton, California — Live
Live readings from PurpleAir sensors across Stockton — with free alerts the moment the air turns.
AQI 13 from 4 PurpleAir sensors · Trending up · data from PurpleAir
As of , the air quality in Stockton, California is AQI 13 — Good and rising — with PM2.5 at 2.4 µg/m³, the median of 4 live PurpleAir sensors reading 8 to 16. Canairy's verdict: Breathe easy.
For scale, that PM2.5 reading is below the World Health Organization's 24-hour guideline of 15 µg/m³. The WHO figure is a daily average and this is a live reading, so read it as a sense of magnitude rather than a formal exceedance — a brief spike and a bad day are not the same thing. More on the WHO guidelines
Pollen today in Stockton: weeds pollen is the strongest of the three at a low level, from Google's pollen forecast. Canairy shows the tree, grass and weed forecast beside the air reading on every plan, including the free one.
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Stockton and Lodi, Manteca, Tracy, Lathrop. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Stockton
The sensors Canairy reads in Stockton agree right now — all 4 sit in the Good band, a 8-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 0.9 mi W | 8 | Good |
| 2.3 mi SSW | 12 | Good |
| 2.4 mi SE | 16 | Good |
| 3.1 mi NNE | 14 | Good |
Stockton sits at the north end of the San Joaquin Valley, a flat basin walled in by the Sierra Nevada and the Coast Ranges that traps whatever gets into the air. The result is some of the harder air in the country: San Joaquin County has ranked among the ten most particle-polluted counties in the nation, and the mix here is year-round, from freight diesel and the inland port to winter wood smoke and the wildfire haze that rolls in most summers.
What Canairy does for Stockton
A clear verdict
Not just a number — a plain-English call for Stockton: open the windows, or keep them shut.
Smoke alerts
A push or text the moment the air crosses your threshold — and again when it clears.
A heads-up before it's bad
Trend alerts catch the air turning, so you can close up the house before the smoke settles in.
Every place you care about
Home, work, the kids' school — across Stockton or across the country, on one screen.
What the air in Stockton is doing next
| When | AQI | Expected air quality | Main pollutant |
|---|---|---|---|
| Today | 33 | Good | PM2.5 |
Forecast from EPA AirNow for the Stockton reporting area. Canairy watches the live sensors against it and tells you when the air actually crosses your threshold, rather than leaving you to check.
The Valley basin holds the air still, especially in winter
Stockton's geography is the whole story. The city sits on the valley floor between the Sierra Nevada to the east and the Coast Ranges to the west, and that bowl shape limits the wind that would otherwise clear things out. On hot, calm summer days pollution simply accumulates, and in winter it gets worse: cold air settles on the valley floor with warmer air sitting on top of it like a lid.
That winter inversion is what drives the Tule fog season and traps fine particles close to the ground for days at a time. When the air stops moving, everything that's already here — freight exhaust, wood smoke, dust — has nowhere to go, which is why the Valley's worst particle readings tend to come on still, foggy winter mornings rather than during a storm.
Freight, the inland port, and the freeways carry a year-round load
Stockton is a freight town. Interstate 5 and State Route 99 run diesel trucks through the city day and night, rail lines move freight, and the Port of Stockton — one of California's inland deepwater ports — brings ships, locomotives, and distribution-warehouse equipment right up against residential neighborhoods. This is pollution that doesn't wait for fire season or a cold snap; it runs all year.
The burden falls hardest on south and southwest Stockton. The Boggs Tract neighborhood near the port and I-5 sees more diesel exhaust than 74 percent of California neighborhoods and an asthma rate higher than 98 percent of the state, and the port area scores in the top percentile for pollution burden statewide. The state named these areas an AB 617 community, which brings extra air monitoring and clean-air funding to the parts of town carrying the most exposure.
Wildfire smoke and winter wood smoke are the two seasonal spikes
On top of the year-round freight load, Stockton gets two seasonal surges. In summer and fall, smoke drifts in from fires in the Sierra Nevada foothills and across Northern California, and the same basin that traps everyday pollution holds the smoke too. In 2020 wildfire smoke was the single largest contributor to the city's air pollution, and at its worst the PM2.5 concentration reached about 16 times the World Health Organization's annual guideline as smoke from fires like the August Complex settled over the region.
Winter brings the second spike from residential wood burning. Because wood smoke is one of the largest sources of wintertime fine particles in the Valley, the San Joaquin Valley Air District runs its 'Check Before You Burn' program from November 1 through the end of February, issuing a daily burn status for the county based on the forecast. On a 'no burning' day, lighting a fireplace isn't just discouraged, it's against the rule — and checking the day's status before you burn is the simplest thing a household here can do for the shared air.
Stockton air quality FAQ
What is the air quality in Stockton right now?
As of September 5, 2026 at 5:10 AM PDT, the air quality in Stockton, California is AQI 13 — Good — with PM2.5 at 2.4 µg/m³, the median of 4 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why is Stockton's air worse in winter?
Stockton sits in a valley basin, and in winter cold air settles on the valley floor with warmer air on top of it like a lid. That inversion traps fine particles close to the ground, brings the Tule fog, and holds pollution in place for days. Winter wood smoke adds to it, which is why the San Joaquin Valley Air District runs its 'Check Before You Burn' program from November through February with a daily burn status for the county.
Which parts of Stockton have the worst air?
The heaviest burden falls on south and southwest Stockton, near the Port of Stockton, the rail lines, and Interstate 5. The Boggs Tract neighborhood there sees more diesel exhaust than most of California and one of the highest asthma rates in the state. The state designated these areas an AB 617 community, which brings extra air monitoring to the parts of town carrying the most freight and industrial pollution.
What the AQI numbers mean
| AQI | Category | What it means for you |
|---|---|---|
| 0–50 | Good | Open the windows. Great for outdoor activity. |
| 51–100 | Moderate | Sensitive groups may want to take it slower outside. |
| 101–150 | Unhealthy for Sensitive Groups | Kids, elderly, and respiratory conditions stay closer to home. |
| 151–200 | Unhealthy | Skip outdoor exercise. Close windows. |
| 201–300 | Very Unhealthy | Limit time outside. N95 if you must go. |
| 301+ | Hazardous | Health emergency. Stay inside, run filtration if you have it. |
Canairy lets you tighten these bands if you’re more sensitive than the EPA default, so an alert can fire before the official category changes. How to read the Air Quality Index
Where these readings come from
The AQI at the top of this page is the median of the 4 curated PurpleAir sensors Canairy tracks in and around Stockton, with outliers set aside so that one sensor brought indoors — or parked beside a barbecue — cannot set the number for a whole city. Every sensor behind it is listed above with its distance and bearing from the city center. There is no black box here.
In the app, a place you save resolves the same way first. When no neighborhood sensor is reporting it falls back to the nearest EPA AirNow monitor, and anything modeled rather than measured is labelled a regional estimate rather than passed off as a sensor reading. How low-cost sensors compare to regulatory monitors
About Canairy
Canairy is free to download. The free plan covers one saved place with live readings, a plain-English verdict, and push alerts when the air crosses a threshold you choose. Paid plans add more places, faster refreshes, and SMS alerts. It is built by two parents in Sonoma County, California, who got tired of guessing whether it was safe to send the kids outside. Why we built it
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Air quality near Stockton
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