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.

Live Newark AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Newark and Bear, Glasgow, Christiana, Elkton, MD.

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.

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.

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, DE right now?

This page shows the current AQI for Newark, calculated from PurpleAir sensors across the city and updated continuously. The map below shows every live sensor, so you can check the reading closest to your own neighborhood.

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 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.

Where does Canairy's Newark data come from?

Readings come from PurpleAir's network of laser particle sensors across Newark and surrounding New Castle County towns, cross-referenced with government monitors and the Google Air Quality API. You can see every sensor behind your numbers on the live map - there's no black box.

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.