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.
AQI 37 from 5 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Manchester, New Hampshire is AQI 37 — Good and falling — with PM2.5 at 6.6 µg/m³, the median of 5 live PurpleAir sensors reading 31 to 47. 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 Manchester: weeds pollen is the strongest of the three at a low 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 Manchester and Bedford, Londonderry, Hooksett, Goffstown. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Manchester
The sensors Canairy reads in Manchester agree right now — all 5 sit in the Good band, a 16-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 0.6 mi NNE | 38 | Good |
| 0.8 mi W | 47 | Good |
| 1.3 mi E | 31 | Good |
| 2.3 mi N | 37 | Good |
| 2.7 mi NE | 31 | Good |
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.
What Canairy does for Manchester
A clear verdict
Not just a number — a plain-English call for Manchester: 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 Manchester or across the country, on one screen.
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?
As of September 14, 2026 at 8:10 AM EDT, the air quality in Manchester, New Hampshire is AQI 37 — Good — with PM2.5 at 6.6 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
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 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 Manchester, 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 Manchester
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