Air Quality in Newark, Delaware — Live
Live readings from PurpleAir sensors across Newark, DE — with free alerts when summer ozone or wildfire smoke rolls in.
AQI 14 from 4 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Newark, Delaware is AQI 14 — Good and falling — with PM2.5 at 2.5 µg/m³, the median of 4 live PurpleAir sensors reading 8 to 18. 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 Newark: 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 Newark and Bear, Glasgow, Christiana, Elkton, MD. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Newark
The sensors Canairy reads in Newark agree right now — all 4 sit in the Good band, a 10-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 1.4 mi ESE | 8 | Good |
| 2.3 mi SW | 18 | Good |
| 4.8 mi NE | 10 | Good |
| 5.2 mi S | 18 | Good |
For most of the year, the air around Newark is unremarkable in a good way — this isn't a wildfire town. New Castle County's real air problem is summer ozone: Newark sits inside the Philadelphia-Wilmington-Atlantic City ozone nonattainment area, and the combination of I-95 traffic running straight through town and hot, humid summer afternoons is what keeps the county's ozone grade stuck at a D most years. Real wildfire smoke does show up too, just rarely — in June 2023, smoke that drifted down from Canada pushed New Castle County's air quality index into the Hazardous range, something most Newark residents had never seen before.
What Canairy does for Newark
A clear verdict
Not just a number — a plain-English call for Newark: 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 Newark or across the country, on one screen.
What the air in Newark is doing next
| When | AQI | Expected air quality | Main pollutant |
|---|---|---|---|
| Today | 42 | Good | ozone |
| Tomorrow | 48 | Good | ozone |
Monday, September 14: Moderate northerly winds will disperse pollutants and keep the lower levels of the atmosphere well mixed as a cold front departs to the south. Therefore, despite increasing sunshine aiding ozone production during the afternoon, AQI levels are anticipated to be Good for ozone and PM2.5. Tuesday, mostly sunny skies throughout the day will allow ozone development to increase. However, light easterly to southeasterly winds will recirculate a clean air mass across the state. As a result, Good AQI levels are anticipated for ozone and PM2.5. Wednesday, a ridge of high pressure aloft will hinder atmospheric mixing. Furthermore, mostly sunny skies and highs in the low 80s will aid ozone formation, while light south-southwesterly winds limit dispersion. However, pollutant carryover from the previous days will be low. Therefore, high-Good AQI levels are anticipated for ozone and PM2.5.
Forecast from EPA AirNow for the Greater New Castle 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.
Newark's real air problem is summer ozone, not smoke
Newark and the rest of New Castle County are classified a 'Serious' nonattainment area for the 2015 ozone standard, part of the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE nonattainment zone under EPA rules — one of the tougher rungs on that ladder. In the American Lung Association's 2026 'State of the Air' report, New Castle County held a D grade for ozone smog, averaging about 2.7 unhealthy-ozone days a year, the worst mark of Delaware's three counties, while the broader Philadelphia-Reading-Camden metro area it belongs to was ranked 43rd worst in the nation for ozone.
The cause is mundane rather than dramatic: I-95, the Delaware Turnpike, runs directly through Newark, and tailpipe exhaust cooking in summer heat and sunlight is the textbook recipe for ground-level ozone. Unlike smoke, ozone builds quietly over a still, hot afternoon and is often worst not right at the roadside but a few miles downwind by mid-afternoon — which is why one reading from one spot in town doesn't tell the whole story of a Newark summer day.
The Canadian wildfire smoke of June 2023 was the real exception
Newark doesn't usually deal with wildfire smoke, which is exactly why the smoke rolling down from Canada in June 2023 stood out. On June 8, 2023, DNREC recorded New Castle County's air quality index in the 301-500 Hazardous range — the worst category on the scale — as smoke from Quebec's record fire season blanketed the mid-Atlantic, and the state told residents to stay indoors entirely, a step Delaware rarely takes.
The smoke came back later that month: DNREC declared a Code Red Air Quality Action Day for June 29, 2023, after haze and a burning odor settled back over the state on June 28. The University of Delaware, whose campus sits in the middle of Newark, posted its own alert telling students and staff to limit time outdoors — a reminder that even a city whose air is ordinarily fine can end up under some of the worst readings in the country when smoke from hundreds of miles away finds the right wind.
Not every bad day traces back to weather
New Castle County's air isn't only shaped by cars and campfires. The Delaware City Refinery, roughly a dozen miles southeast of Newark on the Delaware River, has a documented history of equipment failures that spike sulfur dioxide and other emissions — in one stretch in May 2025 the refinery released 745 tons of sulfur dioxide and more than 50 tons of nitrogen oxides in about three weeks, according to state records, and DNREC has fined the plant's owner, PBF Energy, repeatedly over incidents like it.
Those releases tend to land on Delaware City and New Castle more than on Newark itself, since the refinery sits well to the southeast, but they're a real part of why DNREC runs a dense monitoring network across the county instead of relying on one number for the whole area. It's the same reason Canairy reads sensors near the places you've actually saved instead of a single county-wide reading.
Newark air quality FAQ
What is the air quality in Newark right now?
As of September 14, 2026 at 11:54 AM EDT, the air quality in Newark, Delaware is AQI 14 — Good — with PM2.5 at 2.5 µg/m³, the median of 4 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why did Newark's air quality get so bad in June 2023?
Smoke from a record wildfire season in Quebec drifted south and settled over the mid-Atlantic. On June 8, 2023, DNREC recorded New Castle County's air quality index in the Hazardous range (301-500), and the state issued a Code Red Air Quality Action Day again on June 29 after the smoke returned. Both were rare enough that officials told residents to stay indoors entirely, which doesn't happen in a typical Newark summer.
Does Newark, Delaware have an ozone problem?
Yes, more than most people expect for a small city. Newark and the rest of New Castle County are classified a 'Serious' nonattainment area for ground-level ozone under the Philadelphia-Wilmington-Atlantic City designation, and the American Lung Association's 2026 State of the Air report gave the county a D grade for ozone smog. I-95 runs directly through town, and traffic exhaust combined with hot, sunny summer afternoons is the main driver.
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 Newark, 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
Go deeper
Air quality near Newark
We watch Newark's air. You live your life.
Set your threshold once and get a heads-up only when the air actually changes for you. Free on the App Store & Google Play.