Air Quality in Concord, New Hampshire — Live

Live readings from PurpleAir sensors across Concord — with free alerts when summer ozone or wildfire smoke push the air past healthy.

Live Concord AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Concord and Bow, Hopkinton, Pembroke, Loudon.

Concord's air is good on most days of the year — this is a small state capital in the Merrimack River valley, not a place known for pollution. The two things that actually move the needle are summer ground-level ozone, driven by heat and regional traffic along the I-93 corridor, and — a newer pattern — smoke drifting down from Canadian wildfires that has triggered a growing share of New Hampshire's air quality alerts since 2023.

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.

Why Concord gets ozone alerts on hot days

New Hampshire has belonged to the Ozone Transport Region since the Commission was created under the Clean Air Act in 1991 — a corridor of 13 states plus Washington, D.C. stretching from Virginia to Maine, set up because ground-level ozone drifts across state lines faster than any one state can regulate it. Concord sits inside that corridor, threaded by I-93 and I-89, so on a hot, still afternoon the exhaust and industrial emissions pushed north from Boston and the rest of southern New England mix with local traffic and push the numbers into unhealthy territory for people with asthma or heart conditions.

That's what happened in late May 2024, when an early-season heat wave pushed New Hampshire's Department of Environmental Services to issue back-to-back ozone advisories. "Maybe hold off on going for your afternoon run or any outdoor exercise in general," the department's Air Quality Analysis Supervisor, Marcus Chase, told New Hampshire Public Radio. Dr. Paul Friedrichs, of New Hampshire Health Care Workers for Climate Action, explained the mechanism at the time: heat and combustion — cars, power plants — drive ground-level ozone higher, compounding whatever fine-particle pollution is already in the air.

Canadian wildfire smoke is becoming a summer regular

For most of Concord's history, wildfire smoke was someone else's problem. That's changed. In summer 2025, six of the eight air quality alerts New Hampshire DES issued statewide were triggered by smoke drifting down from Canadian wildfires rather than local pollution. "Something that used to not be part of our routine is now routine," state air quality scientist Kathleen Simmons told New Hampshire Public Radio in August 2025.

It isn't a one-off year. Canadian wildfire smoke forced DES to declare air quality action days over the weekend of June 30 to July 2, 2023, hitting the western half of the state and anywhere above 2,000 feet elevation hardest, and lingering smoke was still triggering advisories in Grafton, Sullivan, and Cheshire counties as recently as August 2025. Those alerts are issued statewide, so Concord sits under the same advisory even on days when the reporting focuses on the hillier counties to its west.

Why one number for Concord isn't the whole story

Concord straddles the Merrimack River, with downtown sitting on a low terrace west of the water and the Soucook River marking the city's eastern edge. Step outside the urban core and the city is ringed by small, heavily wooded towns — Bow, Hopkinton, Pembroke, Canterbury, Loudon — that look and behave nothing like the blocks around the State House a few miles away.

A single ozone or smoke reading reported for Concord or Merrimack County can miss that difference entirely. Canairy reads the actual PurpleAir sensors near the places you've saved instead of one faraway monitor, so a reading near downtown can look different from one out past Penacook or toward the Bow town line — useful on the handful of days a year when the difference actually matters.

Concord air quality FAQ

What is the air quality in Concord, New Hampshire right now?

This page shows the current AQI for Concord, 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, whether that's downtown, Penacook, or out toward Bow.

Why does Concord get ozone alerts in summer?

New Hampshire sits inside the Ozone Transport Region, a multi-state corridor where heat and regional traffic combine to push ground-level ozone higher. In late May 2024, an early heat wave triggered back-to-back DES ozone advisories for the state, with officials recommending sensitive groups skip outdoor exercise in the afternoon.

Does wildfire smoke reach Concord, New Hampshire?

Yes, increasingly. Six of New Hampshire's eight air quality alerts in summer 2025 were caused by smoke drifting down from Canadian wildfires rather than local pollution, and the same pattern showed up in 2023 and 2024. State officials now describe wildfire smoke as a routine part of New Hampshire summers rather than a rare event.

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.

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.

Where does Canairy's Concord data come from?

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

Get Canairy free on Google Play.