Fredericton Real-Time AQI Tracker
What's Actually In Fredericton Air Today?
What High AQI Means for Your Lungs in Fredericton
How to Read AQI
The Air Quality Index (AQI) measures how polluted the air is and how it may affect your health.
0–50 (Good): Air quality is satisfactory.
51–100 (Moderate): Acceptable, but some pollutants may pose minor concerns.
101–150 (Unhealthy for Sensitive Groups)
151–200 (Unhealthy)
201–300 (Very Unhealthy)
301+ (Hazardous)
Moderate
Still okay for most, but if you have asthma or allergies, take it easy and avoid long outdoor workouts.
Shop MERV 11 filters→What's the Right Filter for Your AQI Level?
Live Air Quality Index AQI Map Fredericton, NB Today
TL;DR
Fredericton's live air quality index is on the map above, and the official Canadian measure is the AQHI, a 1 to 10+ scale updated hourly. The city's provincial station at 486 Needham Street measures all three AQHI pollutants: fine particulate matter (PM2.5), ground-level ozone and nitrogen dioxide. In 2024, that station met every national air quality standard it reports against, with ozone sitting closest to its limit. When smoke or smog pushes the reading up, close the windows and run your furnace fan through a clean, higher-rated filter.
Key Takeaways
Fredericton's official air quality measure is the AQHI (1 to 10+); many global apps show the U.S. AQI (0 to 500) instead.
New Brunswick's Department of Environment and Local Government runs Fredericton's station at 486 Needham Street, measuring PM2.5, ozone and nitrogen dioxide.
In 2024, Fredericton's ozone reached about 81% of its national standard, PM2.5 52% to 59%, and nitrogen dioxide 12% to 38%.
New Brunswick issued a single air quality advisory in all of 2024, for Woodstock and Carleton County after a structure fire.
During wildfire smoke events, the AQHI switches to a PM2.5-only formula, so rising smoke shows up in the index faster.
What Is the Air Quality in Fredericton Today?
For live, real-time air quality in Fredericton right now, the map above gives the fastest answer, refreshed hourly. For the official number, Environment and Climate Change Canada (ECCC) posts Fredericton's current AQHI plus forecast maximums for the next two days and nights.
Filterbuy cross-checked all three real-time sources for this page:
The live map (this page): a quick visual check of the Fredericton air quality map, including PM2.5.
ECCC's Fredericton AQHI page: the official AQHI with its risk category and forecast. Check it here.
New Brunswick's Air Quality Data Portal: hourly station results, including Fredericton PM2.5 today as a concentration. Open the portal.
ECCC notes that live AQHI values skip detailed quality control, so if one hour looks odd, wait for the next reading.
Where Fredericton's Air Quality Readings Come From
Fredericton's AQHI uses data collected inside the city. The New Brunswick Department of Environment and Local Government (DELG) operates the station at 486 Needham Street, which measures all three AQHI pollutants (PM2.5, ground-level ozone and nitrogen dioxide) plus weather data.
Filterbuy maps monitoring coverage for cities across Canada, and many borrow their AQHI from a neighbouring community's station. Fredericton doesn't: its readings come from the capital itself.
Monitoring in New Brunswick is a federal-provincial partnership. According to the Government of New Brunswick, DELG runs and calibrates the instruments, ECCC oversees data quality, and Health Canada calculates the hourly AQHI from the station data.
How Clean Is Fredericton's Air? What the 2024 Provincial Data Shows
Fredericton's air met every national standard it was measured against in 2024. DELG's 2024 Air Quality Monitoring Results report, tabled in December 2025, shows the Needham Street station achieving the Canadian Ambient Air Quality Standards (CAAQS) for all three pollutants it measures.
No other air quality page we found shows how close Fredericton sits to each standard, so Filterbuy worked it out: each value comes straight from DELG's report, divided by its national limit. Nothing is estimated. CAAQS values are multi-year statistics built to track trends.
Source: DELG, 2024 Air Quality Monitoring Results. Share of limit calculated from the reported CAAQS values.
How to Read Fredericton's AQHI and the AQI Some Apps Show
The AQHI runs from 1 to 10+ and sorts readings into four health risk categories. It combines the relative health risk of PM2.5, ozone and nitrogen dioxide into one number, so a higher value means more reason to adjust strenuous outdoor plans. Health Canada and ECCC define people at risk as children, adults over 65 and people with health conditions.
Three patterns stood out when we ran the numbers:
Ozone sits closest to its limit. Despite a Green management level, ozone reached about 81% of the standard. ECCC explains that ozone forms in sunlight and travels long distances, so summer weather and regional air movement shape it more than local traffic.
Traffic pollution is low. Nitrogen dioxide, linked mainly to vehicle exhaust, reached just 12% of its annual limit.
Fine particles sit mid-range for the region. Fredericton's annual PM2.5 value of 5.2 sat well below Edmundston's Rice Street station (8.4), which set the central air zone's Orange level.
Filterbuy's read: in Fredericton, plan around hot summer afternoons and smoke events, not the daily commute. Province-wide, New Brunswick issued one air quality advisory in 2024, for Woodstock and Carleton County after a structure fire. The report predates the 2025 wildfire season, so rely on the live map for current conditions.
How Fredericton Compares With Other New Brunswick Cities
Against the province's other large monitored cities in the same report:
Traffic pollution: 1-hour nitrogen dioxide of 23 ppb, below Moncton (29), Saint John's Castle Street (31) and Edmundston (32).
Fine particles: annual PM2.5 of 5.2, level with Moncton (5.3) and Saint John's Castle Street (5.1).
Ozone: 50 ppb, the very top of the Green band (0 to 50). Saint John's Castle Street (52) has already tipped into Yellow.
To reach Green, annual PM2.5 would need to fall about 23%, from 5.2 to 4.0, which puts wood smoke and wildfire smoke, two particle sources DELG flags, in focus.
Source: Government of Canada, About the Air Quality Health Index (updated May 2026).
During a wildfire smoke event, ECCC adjusts the formula and calculates the hourly AQHI from PM2.5 alone, which lets the index respond quickly as smoke moves in.
Many global apps show a Fredericton AQI instead, converted to the U.S. Air Quality Index (0 to 500). On that scale, AirNow rates 0 to 50 as Good, 51 to 100 as Moderate and 101 to 150 as Unhealthy for Sensitive Groups.
Is the Air Quality Bad in Fredericton Today? What Moves the Number
Usually not. The 2024 data above shows no standard exceeded, and the province's only advisory that year was issued elsewhere. When Fredericton air pollution does rise, DELG and ECCC point to a short list of common causes:
Wildfire smoke. Smoke can lift PM2.5 quickly, sometimes from fires far outside the province. Health Canada's wildfire smoke guidance explains how to check conditions during a smoke event.
Summer ozone. Hot, sunny weather drives ground-level ozone, which is generally low in winter.
Wood smoke in colder months. DELG notes that residential wood heating can affect local air quality through the heating season.
Long-range pollution. Fine particles and ozone also drift in from other regions.
With heating season starting in late September, wood smoke becomes the local factor to watch on cooler evenings.
How to Keep Indoor Air Clean in Fredericton Homes
Official guidance comes first: follow ECCC air quality alerts and any advice from New Brunswick officials. Filtration is one layer on top of that. The U.S. Environmental Protection Agency recommends a filter rated MERV 13 or higher in a central HVAC system during smoke events. The EPA also notes that most furnaces and HVAC systems can use one without equipment problems when it's replaced often.
Filterbuy's rule: when the map shows an AQI of 100 or higher, take these four steps. We act at 100, the top of the Moderate range, so homes are ready before air reaches the Unhealthy for Sensitive Groups category.
Switch your HVAC to a MERV 13 (Optimal) filter. It's the whole-home layer, and fitting it is the same check as confirming your size.
Set the thermostat fan to On, not Auto, so the system filters continuously, even without heat.
Run a portable HEPA air cleaner in each occupied room, bedrooms first. Choose a smoke CADR of at least two-thirds of the room's floor area: a 28 m² (300 sq ft) bedroom needs about 200. Skip ionizers and ozone generators; the EPA advises against air cleaners that produce ozone.
Close the house up. Shut windows and doors, and don't add indoor pollution: no candles, frying or smoking, and no vacuuming without a sealed unit. On winter evenings, that includes chimney smoke; here is what to do when a neighbour's wood smoke gets indoors.
No ductwork? In apartments and homes without central HVAC, portable HEPA air cleaners are your main defence, not a backup. Renting? Ask your landlord which filter the system takes.
During smoke, check the filter often and replace it when it looks dark brown or black, which can be well before the normal interval. Keep a spare on hand. Pleated filters capture particles, not the gases behind smoke smell; for odours, see the Odour Eliminator line.
Outside smoke events, a fresh filter every 60 to 90 days keeps airflow steady through Fredericton's long heating season. At Filterbuy.ca, we carry MERV 8 (Standard), MERV 11 (Superior), MERV 13 (Optimal) and Odour Eliminator filters, and we colour-code every rating so the right one is easy to spot at reorder time. With over 600 sizes and custom sizes available, plus free shipping to Canada with no minimum, finding an exact fit is simple. Our guide to MERV ratings explains the differences.
Michelle Wan, who writes Filterbuy's air quality guides, often hears that changing a filter more often fixes a pollution problem. Her answer:
"The rating matters far more than the schedule. A fresh MERV 8 filter still lets most fine particles through, while a MERV 13 filter catches far more of them."
Michelle Wan, Brand Manager and Air Quality Writer, Filterbuy
Supporting Statistics
U.S. federal research backs this guidance:
Asthma emergency visits rose 17% on smoke days.
CDC tracked 4,317 U.S. emergency departments.
The rise held across 19 smoke days in 2023.
The smoke came from wildfires in Canada.
Source: CDC MMWR, August 2023
Wildland fires produced 52% of U.S. PM2.5 emissions.
The figure comes from EPA's 2020 National Emissions Inventory.
It makes wildfire smoke the largest single source of fine particles.
Source: U.S. EPA, Wildland Fire Research
Closed-up homes hold indoor PM2.5 to about 55% to 60% of outdoor levels.
This applies during smoke, with doors and windows shut and no air cleaner running.
The range runs from 30% to 100%, depending on the home.
With windows open, indoor and outdoor levels end up similar.
Trusted Sources for Fredericton Air Quality
Filterbuy carries filters, not monitoring stations. These are the sources we checked while building this page:
ECCC: Fredericton AQHI. Official current AQHI and forecast maximums.
New Brunswick Air Quality Data Portal. Hourly readings from every station in the province.
Government of Canada: About the AQHI. Scale, health messages and how the index is calculated.
Government of New Brunswick: Air quality monitoring. Station list and air zone details.
Health Canada: Wildfire smoke, air quality and your health. Official guidance for smoke events.
Filterbuy.ca: Live AQI map for Canada. Compare Fredericton with other Canadian cities.
Filterbuy.ca: Live wildfire and smoke map for New Brunswick. Active fires and smoke across the province.
Frequently Asked Questions
Is the air quality bad in Fredericton today?
Check the live map on this page or ECCC's Fredericton AQHI. An AQHI of 1 to 3 is low risk, 4 to 6 is moderate and 7 or higher is high. Elevated readings are usually tied to wildfire smoke or summer ozone.
What is Fredericton's PM2.5 today?
New Brunswick's Air Quality Data Portal lists hourly PM2.5 concentrations from the Needham Street station. The live map here also shows PM2.5. For background, see how PM2.5 differs from PM10.
Where is Fredericton's air quality monitoring station?
Fredericton's station is at 486 Needham Street. DELG runs it, measuring PM2.5, ozone, nitrogen dioxide and weather.
What is the difference between AQI and AQHI?
The AQHI is Canada's official 1 to 10+ scale, built from the combined health risk of three pollutants. The AQI is the U.S. 0 to 500 scale, driven by the highest single pollutant.
How often is Fredericton's air quality updated?
Hourly. ECCC also issues AQHI forecasts twice daily, at 6:00 a.m. and 5:00 p.m. local time.
What filter is best for wildfire smoke in Fredericton?
MERV 13. A Filterbuy MERV 13 (Optimal) filter is the tier we recommend for smoke, paired with a portable HEPA air cleaner in each occupied room. Separately, the EPA recommends MERV 13 or higher in central HVAC systems during smoke events. Pleated filters don't capture smoke odour, which is a gas.
Glossary
AQHI (Air Quality Health Index): Canada's 1 to 10+ health risk scale for local air.
AQI (Air Quality Index): The U.S. EPA's 0 to 500 scale, reported for the highest single pollutant.
PM2.5: Fine particles 2.5 micrometres or smaller, largely from smoke and vehicle exhaust.
Ground-level ozone (O3): A gas formed by sunlight-driven reactions; a main part of summer smog.
Nitrogen dioxide (NO2): A gas released mainly by vehicle exhaust and fuel burning.
CAAQS: Canadian Ambient Air Quality Standards, the national benchmarks for outdoor air.
Management level: The CAAQS colour grade (Green to Red) for a station or air zone.
DELG: New Brunswick's Department of Environment and Local Government.
ECCC: Environment and Climate Change Canada, which publishes AQHI forecasts.
ppb and µg/m³: Units for pollutant levels: parts per billion for gases, micrograms per cubic metre for particles.
HEPA: High-efficiency particulate air, a filter type used in portable air cleaners, not furnace slots.
CADR: Clean Air Delivery Rate, how much filtered air a portable cleaner delivers.
MERV: Minimum Efficiency Reporting Value, a rating of how well an HVAC filter captures particles.
Your Next Steps for Cleaner Air in Fredericton
Bookmark this page and check the map and ECCC forecast before outdoor plans.
Check the date on your furnace filter. If it's been more than 60 to 90 days, it's due; during smoke, check it sooner.
Match the filter to your home: MERV 11 (Superior) for everyday allergens, MERV 13 (Optimal) for smoke and fine particles, or Odour Eliminator for smells.
Set up Filterbuy Subscribe and Save so a fresh filter arrives on schedule. Edit, skip or cancel anytime.
Filterbuy's take: the reading outside changes hourly, but the filter inside is yours to control. A clean one reduces the particles circulating in your home through smoke season and winter. Find Your Size | Subscribe and Save