Air Quality in Rochester, New Hampshire — Live

Live readings from PurpleAir sensors across Rochester — with free alerts the moment the air actually changes.

Live Rochester AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Rochester and Dover, Somersworth, Farmington, Barrington.

Rochester's air is good most of the year — this is coastal New Hampshire, not a smog basin, and there's no mountain ring here to trap anything in place. What actually shows up in Rochester's air comes from three specific, unrelated sources: the Turnkey Landfill on the city's east side, which has drawn years of resident odor complaints; hot, hazy summer afternoons when ozone drifts up the Northeast corridor from Boston and beyond; and, in June 2023, smoke from Canadian wildfires that pushed particle pollution to unhealthy levels statewide for a couple of days.

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.

Rochester's air problem has a street address

Most cities' air-quality stories are about weather and geography. Rochester's is also about a specific 1,300-acre property at 176 Rochester Neck Road: the Turnkey Landfill, one of the largest waste facilities in New England, taking in more than a million tons of trash a year from across the Seacoast region and beyond. Landfill gas from the site is collected and burned in flares and gas-to-electric plants — enough to power roughly 7,000 homes and to supply fuel to UNH's Durham campus — but the process isn't airtight.

Starting in 2023, Rochester residents reported the odor getting noticeably worse, and Waste Management's director of disposal operations, Steve Poggi, told the city council that October the company had taken 'immediate and aggressive action to correct the causes.' Five residents petitioned the EPA in February 2024 to block the site's Title V air permit; the agency denied that petition in August 2024, and the state approved a 60-acre expansion of the landfill in October 2023 regardless. The smell isn't the same thing as the particle count on a sensor, but it's the reason a lot of people in Rochester check the air before they decide whether to open a window.

Summer haze usually isn't made here — it arrives here

On hot, humid, windless days, New Hampshire's Department of Environmental Services sometimes issues a statewide Air Quality Action Day for ground-level ozone. The state's own description is blunt about where it comes from: the pollution is 'the result of winds transporting pollutant emissions into New Hampshire from surrounding areas, which combine with local emissions' — meaning car and power-plant exhaust from Boston, New York, and everywhere in between, cooked into ozone by sunlight as it drifts north up the I-95 corridor.

New Hampshire has actually been trying to get out from under this problem at the policy level: it's part of the Ozone Transport Commission, the regional compact set up under the 1990 Clean Air Act to manage exactly this kind of imported smog, and the state has moved to withdraw from it, arguing decades of vehicle and power-plant cleanup have made the old regional framework less necessary. Action days are rarer than they used to be, but a still, 90-degree July afternoon in Rochester can still push ozone into Moderate or worse.

June 2023 was the exception that proved the rule

For most of Rochester's history, wildfire smoke was something that happened to other regions. That changed in late June 2023, when smoke from wildfires burning across Quebec and northern Ontario rode south on the jet stream and settled over New England. NHDES issued an advisory warning that fine particle pollution would reach levels unhealthy for sensitive groups on June 29 and 30, and the haze was thick enough to see and smell from Rochester to the Seacoast.

It was a one-off by New Hampshire standards, not an annual season the way it is in the Mountain West — but it showed that a fire a thousand miles away can still matter here. Canairy's sensor network is what catches that kind of day early, rather than relying on the sky looking obviously orange before anyone checks a number.

Rochester air quality FAQ

What is the air quality in Rochester right now?

This page shows the current AQI for Rochester, 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 does Rochester sometimes smell bad even when the AQI looks fine?

That's usually the Turnkey Landfill on Rochester Neck Road, one of the largest waste facilities in New England, which has drawn years of resident odor complaints and a 2024 EPA petition over its air permit. Odor and measured particle pollution aren't the same thing - you can smell a landfill on a still day without the PM2.5 reading changing much - but it's the most common local reason people in Rochester check the air before opening windows.

Does wildfire smoke ever reach Rochester, NH?

It's rare, but it happened in late June 2023, when smoke from wildfires burning across Quebec and northern Ontario drifted down into New England. New Hampshire's Department of Environmental Services issued an advisory for fine particle pollution reaching levels unhealthy for sensitive groups on June 29 and 30. Unlike the West Coast, this isn't an annual season here, but a big enough Canadian fire year can still send smoke this far south.

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 Rochester data come from?

Readings come from PurpleAir's network of laser particle sensors across Rochester and surrounding 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.