Air Quality in Hayward, California — Live
Live readings from PurpleAir sensors across Hayward — with free alerts the moment the air turns.
AQI 58 from 4 PurpleAir sensors · Trending up · data from PurpleAir
As of , the air quality in Hayward, California is AQI 58 — Moderate and rising — with PM2.5 at 13.0 µg/m³, the median of 4 live PurpleAir sensors reading 56 to 61. Canairy's verdict: Mostly clear.
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 Hayward: 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 Hayward and San Leandro, Castro Valley, San Lorenzo, Union City. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Hayward
The sensors Canairy reads in Hayward agree right now — all 4 sit in the Moderate band, a 5-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 1.1 mi SSW | 58 | Moderate |
| 1.9 mi ESE | 58 | Moderate |
| 3.7 mi W | 56 | Moderate |
| 5.9 mi SSE | 61 | Moderate |
Hayward's air quality question is really a question about which side of the freeway you live on. Between I-880 and the bay runs the strip that has been Hayward's working edge for a century — canneries once, now food manufacturing and distribution, the Hayward Executive Airport, and a gas-fired power station on the shoreline. East of the freeway, climbing toward Fairview and Castro Valley, the picture is quieter. The bay itself is the city's biggest asset here: the Air District notes that in western Alameda County, onshore air keeps ozone from exceeding health standards in a way it does not inland.
What Canairy does for Hayward
A clear verdict
Not just a number — a plain-English call for Hayward: 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 Hayward or across the country, on one screen.
What's out on the shoreline strip
The Russell City Energy Center is a 600-megawatt natural gas-fired power plant that has run on the Hayward shoreline since August 2013. On 27 May 2021 a steam turbine generator there failed mechanically, causing an explosion and fire that shut the facility down for several months. In May 2023 the California Energy Commission approved a $2.5 million settlement with the operator — the largest in the commission's history — half of it earmarked for clean energy projects in Hayward and half to the state General Fund, after a joint investigation with the CPUC required safety upgrades before the plant could restart.
The rest of the corridor is ordinary industry rather than anything dramatic: manufacturing and distribution for names like Annabelle Candy, Columbus Salame, Shasta and PepsiCo, plus the Hayward Regional Shoreline and the Eden Landing salt ponds beyond it. Hayward has had an industrial smell before. During the Hunt Brothers cannery years, the air around town carried the smell of tomatoes for three months of every canning season.
I-880 is the East Bay's truck freeway
Since I-580 was built in the early 1960s, vehicles over 4.5 tons have been banned from an 8.7-mile stretch of it between Grand Avenue in Oakland and Foothill Boulevard in San Leandro. The Environmental Defense Fund and Aclima later drove every street and highway in Oakland an average of thirty times over eleven months, collecting nearly three million measurements, and found black carbon along I-880 running roughly 80 percent higher than along I-580, nitrogen dioxide about 60 percent higher, and nitric oxide more than double.
Those readings were taken in Oakland, not here — but it is the same freeway carrying the same freight south through San Leandro, Hayward, Union City and Fremont. In Hayward it is joined by State Route 92 crossing to the San Mateo Bridge and by I-238 linking over to I-580, so a lot of regional traffic funnels through a few square miles of the city's west side. Caltrans, the Air District and the City of Oakland are currently studying how air quality along both corridors would change if the I-580 truck ban were lifted.
The airport burns leaded fuel, and sensors can't see it
Hayward Executive Airport sits in the same west-side strip. It is a general aviation field, and piston-engine aircraft still run on leaded aviation gasoline, which remains the largest source of lead air pollution in the United States — over 500 tons a year across roughly 20,000 airports. Hayward Executive is one of 23 California airports covered by a 2014 legal agreement the Center for Environmental Health reached to reduce lead exposure around general aviation fields and push the industry toward unleaded fuel.
In October 2023 the EPA made a final determination that lead emissions from aircraft engines endanger public health, starting the rulemaking to regulate them. Research has found children living near general aviation airports carry higher blood lead levels than children living farther away, and a Santa Clara County study around Reid-Hillview in East San Jose found elevated levels in children downwind of the field. This is worth knowing about and it is not something the map below measures — PurpleAir units read fine particles, not lead.
Hayward air quality FAQ
What is the air quality in Hayward right now?
As of September 11, 2026 at 1:20 AM PDT, the air quality in Hayward, California is AQI 58 — Moderate — with PM2.5 at 13.0 µg/m³, the median of 4 live PurpleAir sensors. Sensitive groups may want to take it slower outside.
Why is there smoke in Hayward today?
Most smoke over Hayward has travelled. The city has no wildland right at its edge the way the hill towns do, so what you smell is usually drifting in from a fire elsewhere in Northern California. In mid-August 2020, when hundreds of lightning-sparked fires ringed the Bay Area at once, IQAir reported readings well into the 200s and 300s in Hayward and Castro Valley. On a cold winter evening with no fire in the news, the more likely answer is wood smoke from fireplaces and stoves sitting under an inversion, which is exactly what the winter Spare the Air alerts and the region's wood burning ban exist to reduce.
The sky looks orange or hazy but the reading says moderate. Which is right?
Both can be. Smoke high in the atmosphere blocks and colours the sunlight without necessarily reaching the ground where you are breathing. On 9 September 2020 smoke from the North Complex and more than twenty other fires turned Bay Area skies orange all day — street lights stayed on, drivers used headlights — and ground-level air quality still read 90, which is moderate. The reverse happens too: air can be genuinely unhealthy on a day that looks merely hazy. That is the case for watching an actual sensor rather than the window.
Is the west side of Hayward worse than the hills?
The sources are concentrated there. The industrial corridor, the power plant, the airport, I-880 and the Route 92 approach to the San Mateo Bridge are all in the flats west of the freeway, while the neighbourhoods east of Mission Boulevard sit above most of it. That said, the bay also works in the west side's favour — onshore air off the water disperses pollution and keeps summer ozone low across western Alameda County. The honest answer is that it depends on the day and the wind, which is why a citywide average is less useful than the sensor closest to your street.
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 Hayward, 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 Hayward
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