Air Quality in Manchester, New Hampshire — Live

Live readings from PurpleAir sensors across Manchester — with free alerts when summer ozone or wildfire smoke rolls in.

Live Manchester AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Manchester and Bedford, Londonderry, Hooksett, Goffstown.

Manchester's air is good most of the year — this is New England, not the Central Valley, and the city has no wildfire risk of its own to worry about. The real story here is summer: on hot, hazy afternoons, Hillsborough County sits downwind of the ozone that Boston, Providence, and the rest of the I-95 corridor cook up and carry north on a southwest wind. That's exactly why federal regulators once classified the Manchester area as part of the Boston-Manchester-Portsmouth ozone nonattainment region. In the last few summers, smoke drifting down from wildfires in Quebec has added a second, less predictable problem on top of that.

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.

Manchester's ozone problem comes from somewhere else

Ground-level ozone forms when pollution from cars, power plants, and industry cooks in strong summer sunlight, and Manchester makes very little of that pollution itself. What it gets is imported: the Manchester area was part of the Boston-Manchester-Portsmouth (SE), NH zone that the EPA classified as moderate nonattainment for the 1997 eight-hour ozone standard, staying out of compliance until it was redesignated to maintenance status on March 4, 2013. On a hot, hazy day with a southwest wind, that history is still the mechanism — precursor pollution rides up the I-95 corridor from greater Boston and beyond, and by the time it reaches Hillsborough County it has had hours to turn into ozone.

New Hampshire's Department of Environmental Services still calls these Air Quality Action Days, issuing them statewide when ozone or fine particles are expected to reach unhealthy levels for sensitive groups. A June 3, 2025 action day, for example, pointed to a mix of local ozone precursors and smoke blown in from Canadian wildfires on the same afternoon — a reminder that Manchester's worst air days are rarely caused by just one thing.

Wildfire smoke from Canada is a newer, real visitor

Manchester doesn't have its own fire season, but it has learned what a distant one feels like. On June 6-7, 2023, smoke from extensive wildfires burning in Quebec rode a stalled low-pressure system over Maine and the Canadian Maritimes into New Hampshire, and conditions turned very unhealthy and, in some areas, hazardous within about a day. NHDES issued seven Air Quality Action Days statewide that year, more than in any prior year on record.

It happened again in 2025: NHDES called statewide action days on June 3, July 27, and August 5 that each cited smoke from Canadian wildfires as a contributing cause. For a city that used to treat wildfire smoke as something that happened to other parts of the country, that's now a near-annual summer event worth checking a sensor for, not just a hazy-looking sky.

Winter is quieter, but the river valley still holds smoke some nights

New Hampshire leans on wood heat more than almost anywhere else in the country — about 5% of homes here use wood as their main heat source, roughly four times the national average, according to the U.S. Energy Information Administration. That's mostly a rural New Hampshire story, concentrated in towns like Keene rather than in the state's biggest city.

Manchester itself is the exception that proves the rule: it's the most urban, least wood-heated place in the state, sitting along the Merrimack and Piscataquog rivers with no steep valley walls to trap air the way a true mountain town would. Still, on a cold, still winter night, whatever wood smoke is in the air has nowhere fast to go, and it's worth a glance at a nearby sensor before you decide the smell outside is nothing.

Manchester air quality FAQ

What is the air quality in Manchester right now?

This page shows the current AQI for Manchester, 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 Manchester get ozone alerts in summer?

Ozone forms when pollution cooks in strong sunlight, and Manchester sits downwind of the whole Boston-to-Providence corridor. On hot, hazy days with a southwest wind, that regional pollution rides north into Hillsborough County and turns into ozone by the afternoon — which is why the area was once federally classified as an ozone nonattainment zone and why New Hampshire still calls Air Quality Action Days on days like these.

Has Canadian wildfire smoke reached Manchester?

Yes. In June 2023, smoke from wildfires burning in Quebec pushed New Hampshire's air to very unhealthy and even hazardous levels within about a day, and NHDES issued a record seven statewide Air Quality Action Days that year. It happened again in 2025, with action days in June, July, and August each citing Canadian wildfire smoke as a factor.

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 Manchester data come from?

Readings come from PurpleAir's network of laser particle sensors across Manchester 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.