Air Quality in Joliet, Illinois — Live
Live readings from PurpleAir sensors across Joliet — with free alerts when diesel traffic or summer ozone push the air into unhealthy territory.
AQI 39 from 5 PurpleAir sensors · Trending up · data from PurpleAir
As of , the air quality in Joliet, Illinois is AQI 39 — Good and rising — with PM2.5 at 7.0 µg/m³, the median of 5 live PurpleAir sensors reading 30 to 51. 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 Joliet: weeds pollen is the strongest of the three at a high 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 Joliet and Plainfield, New Lenox, Shorewood, Crest Hill. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Joliet
The sensors Canairy reads in Joliet are 21 AQI points apart right now, from Good to Moderate, which is the whole reason one city-wide number can mislead you: the median describes air you may not be standing in.
| From city center | AQI | Category |
|---|---|---|
| 1.3 mi W | 34 | Good |
| 2.0 mi WSW | 51 | Moderate |
| 2.1 mi N | 42 | Good |
| 3.2 mi NW | 30 | Good |
| 4.3 mi NNE | 39 | Good |
Joliet's air is usually fine — most days sit in the Good to Moderate range, and there's no dramatic wildfire season here the way there is out West. What actually drives the numbers is a different kind of geography: Joliet sits inside the country's largest inland port, at the crossroads of I-55 and I-80, where diesel trucks move containers out of the CenterPoint Intermodal Center and the BNSF and Union Pacific rail yards around the clock. In summer, that truck exhaust combines with heat and humidity to push ground-level ozone up across greater Chicago, and Will County — including Joliet — sits inside the federally designated Chicago ozone nonattainment area.
What Canairy does for Joliet
A clear verdict
Not just a number — a plain-English call for Joliet: 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 Joliet or across the country, on one screen.
What the air in Joliet is doing next
| When | Expected air quality | Main pollutant |
|---|---|---|
| Today | Good | ozone |
| Tomorrow | Good | ozone |
Forecast from EPA AirNow for the Joliet and Will County 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.
Joliet is the heart of the country's largest inland port
The CenterPoint Intermodal Center spans roughly 6,500 acres across Joliet and neighboring Elwood, built on land that was once the Joliet Army Ammunition Plant. Inside it, BNSF's 770-acre Logistics Park Chicago and the separate Union Pacific Joliet Intermodal Terminal move shipping containers between trains and trucks bound for the I-55/I-80 interchange, one of the busiest freight crossroads in the country. Amazon, Walmart, and dozens of other distribution centers have followed the rail yards in, and Amazon alone now employs roughly 3,500 people in the area.
All of that freight moves by diesel truck for the last mile, and Joliet residents feel it directly: idling engines, truck routes that run past homes and schools, and the fine particulate exhaust that comes with both. A statewide Environmental Defense Fund analysis found that more than 1 in 4 Illinois residents live within half a mile of a warehouse, with facilities concentrated in exactly this kind of freight corridor — and Joliet sits at the center of it, not on the edge.
State lawmakers are pushing back on warehouse diesel pollution
In February 2026, state Sen. Rachel Ventura, who represents Joliet, introduced what she called 'first in the nation' legislation — the Warehouse Pollution Reduction Act, SB3732 — aimed squarely at the diesel truck traffic ringing the city. The bill would have required emissions monitoring at large warehouses, kept truck bays farther from schools, and funded zero-emission infrastructure through a new state fee on warehouse operators.
Ventura was direct about why the bill mattered to her district: 'That truck pollution, especially the diesel particulate matter, has caused a lot of asthma in our area,' she said. The bill missed its committee deadline and didn't advance in the spring 2026 session, but a Joliet-area senator introducing it at all reflects how much local frustration with warehouse-corridor air has built up — this isn't an abstract regulatory debate here, it's about the trucks most Joliet residents drive alongside every day.
Summer brings a second problem: ozone
Will County, including Joliet, is part of the Chicago-Naperville-Elgin ozone nonattainment area, which the EPA designated 'marginal' for the 2015 ozone standard in June 2018. Ground-level ozone forms when vehicle and industrial exhaust cooks in summer heat and sunlight, and the exhaust from tens of thousands of daily truck trips through the CenterPoint corridor is a meaningful part of that mix, alongside the ExxonMobil refinery in neighboring Channahon, about ten miles southwest, which processes roughly 264,000 barrels of crude oil a day.
That refinery has had its own air emissions problems — a federal enforcement action required ExxonMobil to pay $1.5 million in penalties and invest about $10 million in emissions-control upgrades after EPA and Illinois regulators found violations. None of this means Joliet's air is bad every day; it means the bad days cluster in a predictable pattern — hot, still summer afternoons, and stretches when the wind carries corridor or refinery exhaust toward town instead of away from it.
Joliet air quality FAQ
What is the air quality in Joliet right now?
As of September 15, 2026 at 7:10 AM CDT, the air quality in Joliet, Illinois is AQI 39 — Good — with PM2.5 at 7.0 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does Joliet's air quality vary so much by neighborhood?
Joliet sits inside the CenterPoint Intermodal Center, one of the largest inland ports in the country, where diesel trucks move containers between rail yards and the I-55/I-80 interchange around the clock. Neighborhoods closest to the warehouse corridor and truck routes tend to see higher fine-particle readings than neighborhoods farther away, which is why a single citywide number can hide a lot — Canairy reads sensors near the places you actually saved instead.
Does Joliet have an ozone problem in summer?
Yes. Will County, including Joliet, is part of the Chicago-Naperville-Elgin area that the EPA designated marginal nonattainment for ground-level ozone under the 2015 standard. Hot, sunny, low-wind days in summer are when ozone tends to climb, driven by the same vehicle and industrial exhaust that fills the warehouse corridor year-round.
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 5 curated PurpleAir sensors Canairy tracks in and around Joliet, 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 Joliet
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