Caledon Real-Time AQI Tracker
What's Actually In Caledon Air Today?
What High AQI Means for Your Lungs in Caledon
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 Caledon, ON Today
Caledon has no provincial air monitoring station within town limits. The closest is the Air Quality Ontario station in Brampton at 109 McLaughlin Road South: 23.0 km from central Caledon, 23.5 km from Bolton and 28.1 km from Caledon Village. Use the live map at the top of this page for a quick visual, then confirm the official Brampton Air Quality Health Index (AQHI) reading before you plan time outdoors.
TL;DR
Caledon's official air quality reading comes from the Brampton AQHI station, the closest provincial monitor to every Caledon community. Use the live map for current conditions and the AQHI, Canada's 1 to 10+ scale, for health decisions. On high-risk days, close the windows and run your furnace fan with a clean, high-efficiency filter.
Key Takeaways
Caledon has no Air Quality Ontario station; Brampton's is closest to Bolton, Caledon East and Caledon Village.
Brampton sits 23.0 to 28.1 km from Caledon's main communities.
The Brampton station is an urban site measuring the three AQHI pollutants: ozone, PM2.5 (fine particles from smoke and exhaust) and nitrogen dioxide.
Wildfire smoke and summer ozone register at Brampton, but very local sources in rural Caledon may not.
The AQHI runs from 1 to 10+, and a reading of 7 or higher is high risk.
What Is the Air Quality in Caledon Today?
Caledon's air quality today is best checked in two places: the live Caledon air quality map on this page for a real-time visual, and the Brampton AQHI from Air Quality Ontario for the official number, including Environment and Climate Change Canada (ECCC) forecast maximums for later today.
To check Caledon air quality right now:
Look at the live Caledon AQI map at the top of this page for conditions across Peel Region.
Open the Brampton current AQHI page for the official hourly reading and today's forecast.
Check the hourly pollutant charts for the Brampton station to see PM2.5, ozone or nitrogen dioxide individually. Tip from Filterbuy's research: check the chart's date first, as it can open on an older range.
No internet? Call Air Quality Ontario's recorded AQHI line at 1-800-387-7768 (toll-free).
Get warnings by email: sign up for Air Quality Ontario's air quality alerts . The form has no Caledon region, so choose Halton - Peel.
Hourly AQHI readings are automatically polled and not yet verified, so treat them as a live guide.
Where Does Caledon Get Its Air Quality Reading?
Caledon's official reading comes from the Brampton monitoring station. None of the 38 AQHI stations in Air Quality Ontario's network sits in the Town of Caledon, so Filterbuy measured how far the Brampton station is from three Caledon communities, using the ministry's published coordinates.
Nearest station shown in green.
How we calculated this: station coordinates come from Air Quality Ontario station pages and community coordinates from public gazetteer entries. Distances use the haversine formula, rounded to 0.1 km, as straight lines rather than driving routes.
What the Distance Means for Caledon Residents
The Brampton station is an urban site. The Town of Caledon covers 688.82 square kilometres, according to Statistics Canada's 2021 Census profile, and more than 75 per cent of the land is protected Greenbelt.
Regional pollution such as wildfire smoke and summer ozone usually reaches Brampton and Caledon on the same day, so the Brampton AQHI is a reasonable guide for it.
Very local sources are different. Almost 16 square kilometres of Caledon is used for extracting sand, gravel and dolomite. Dust from those pits, a neighbour's fire pit or field work can affect the air on your street without moving the Brampton number.
Caledon's official reading comes from an urban site 23 to 28 km away. Treat the Brampton AQHI as your regional baseline, and if you can see or smell smoke at home, trust that over a distant station.
Filterbuy Canada
Which Station Should You Check?
Filterbuy's distance measurements point to these stations:
Bolton and east Caledon: Brampton first, with the Newmarket station (27.3 km) as a second opinion.
Caledon East and central Caledon: Brampton (23.0 km).
Caledon Village and west Caledon: Brampton (28.1 km), then Milton (38.3 km).
How Do You Read the AQHI for Caledon?
The Air Quality Health Index (AQHI) is Canada's official air quality scale. It runs from 1 to 10+ and combines ground-level ozone, PM2.5 and nitrogen dioxide into a single health-risk number. Many international maps use the U.S. Air Quality Index (AQI, 0 to 500), which is calculated differently and does not convert neatly to the AQHI.
For health decisions in Caledon, use the AQHI. The table summarizes Air Quality Ontario's health messages for each risk level.
AQHI Risk Categories and Health Messages
People with heart or breathing problems are at greater risk and should follow their doctor's usual advice. Source: Air Quality Ontario and Environment and Climate Change Canada.
What Affects Air Quality in Caledon Through the Year?
Caledon has a long heating season. The 1981 to 2010 Albion Field Centre climate normals from Environment and Climate Change Canada show average daily temperatures below 9 degrees Celsius in every month from October to April, with about 140 cm of snow a year.
Spring (April to June): tree and grass pollen from farmland, forests and the Niagara Escarpment.
Summer (June to September): wildfire smoke and ozone. Health Canada notes smoke can travel thousands of kilometres.
October to April: closed windows and about seven months of recirculated indoor air.
A Caledon Filter Calendar
Filterbuy built this schedule from those climate normals and a 90-day filter life:
Late September: fit a fresh filter before the first cold night.
Late December: change it at the 90-day mark.
Late March: change it as the heating season winds down.
Late May or June: switch to a Filterbuy Optimal (MERV 13) filter before wildfire season.
Homes with pets should shorten each gap to about 60 days.
Is the Air Quality Bad in Caledon Today? What to Do at Each AQHI Level
Whether the air in Caledon is bad today depends on the AQHI band and on who is breathing it. A reading of 1 to 3 is low risk for everyone. At 4 to 6, people with heart or lung conditions may notice symptoms. At 7 or higher, most people benefit from limiting strenuous outdoor activity and keeping indoor air as clean as possible.
Low Risk (AQHI 1 to 3)
Open the windows, air out the house and check when you last changed your furnace filter.
Moderate Risk (AQHI 4 to 6)
Carry on normally. Anyone at home with asthma, COPD or heart disease should follow the at-risk guidance in the table above and their doctor's advice.
High Risk (AQHI 7 to 10)
Close windows and doors, and set the thermostat fan to "On"; a furnace filter only cleans air while the blower runs. Skip candles, frying and vacuuming without a HEPA vacuum. Reschedule strenuous outdoor activity and check on older neighbours, especially on rural roads where homes are far apart. If smoke is the cause, follow the smoke-day steps below.
Very High Risk (Above 10)
Official guidance comes first: follow Air Quality Ontario alerts and your local public health unit. Stay indoors as much as possible with windows closed and the fan running, and set up a cleaner air room with a portable air cleaner. Filtration is one layer, not the whole answer. If anyone in your home develops chest tightness, persistent coughing or shortness of breath, call Health811 (dial 811) for free advice from a registered nurse, or call 911 in an emergency.
How Filterbuy Helps Caledon Homes Breathe Easier
Our take: with the nearest station over 20 km away and homes shut from October to April, the furnace filter is the lever a Caledon household controls most directly. Filterbuy Canada carries four filter types in more than 600 sizes, shipped free to Caledon with no minimum order.
Standard (MERV 8): everyday filtration for dust, lint and pollen.
Superior (MERV 11): for pets and seasonal allergies, capturing dust mites, mould spores and dander.
Optimal (MERV 13): our highest rating and the tier we recommend for wildfire smoke.
Odour Eliminator: carbon-infused filters for household odours such as cooking and pets.
Unusual return size? Filterbuy carries custom air filters, and our guide to choosing a MERV rating covers fit.
Filterbuy's Smoke-Day Action Line: AQI 100
Official guidance comes first. Then, when the live map on this page shows an AQI of 100 or higher, Filterbuy recommends four steps, in this order:
Put a MERV 13 filter in your furnace or HVAC system (the whole-home layer).
Set the thermostat fan to On. Auto only filters while the system heats or cools.
Run a portable HEPA air cleaner in each occupied room, bedrooms first (the room-level layer).
Close the house up: windows and doors shut, with no candles, frying, smoking or vacuuming without a HEPA vacuum.
No central HVAC? In an apartment or a home without ductwork, portable HEPA air cleaners are your main defence, not an add-on. HEPA belongs in a portable unit, never in a furnace slot; our MERV 13 vs. HEPA guide explains why.
The U.S. EPA recommends MERV 13 or higher during smoke events and notes most furnaces and HVAC systems can take it without equipment problems when the filter is replaced often. For portable units, EPA's cleaner air room guidance calls for a smoke CADR of at least two-thirds of the room's floor area in square feet: about 200 for a 28 square metre (300 sq ft) bedroom. Choose units that don't produce ozone.
During smoke, check the filter often and replace it when it looks dark brown or black, which can be well before its normal interval. Keep spares on hand.
Researching Caledon, the part that surprised me was the distance. The town's official reading comes from Brampton, so I check the Brampton AQHI for the regional picture and look outside for the local one.
Michelle Wan
Supporting Statistics
1. 77.2 million
Americans exposed to particle pollution spikes
Lived in U.S. counties with unhealthy PM2.5 spikes.
Highest total in 16 years.
2023 Canadian wildfire smoke raised levels in the Midwest and East.
Source: American Lung Association, State of the Air 2025
2. 17%
More asthma emergency visits on smoke days
Asthma emergency visits ran 17 per cent above expected.
Measured on 19 U.S. smoke days during the 2023 Canadian wildfires.
Source: CDC, Morbidity and Mortality Weekly Report, August 2023
3. 55 to 60%
Indoor PM2.5 with the house closed up
With doors and windows closed and no portable air cleaner running, indoor PM2.5 typically sits at 55 to 60 per cent of outdoor levels during smoke.
It varies widely by home, from about 30 to 100 per cent.
Source: U.S. EPA, Strategies to Reduce Exposure Indoors
Frequently Asked Questions
What is the air quality in Caledon today?
Caledon's air quality today is on the live map at the top of this page; the Ontario live air quality map shows the province. For the official reading, check the hourly Brampton AQHI.
Is the air quality bad in Caledon today?
It depends on the current AQHI. A reading of 7 or higher is high risk for everyone, and people with heart or lung conditions may feel effects from 4 upward. If you can see or smell smoke in Caledon, treat the air as poor even if the Brampton number looks fine.
What MERV rating do I need for wildfire smoke?
MERV 13. Filterbuy recommends switching to a MERV 13 filter when the live map shows AQI 100 or higher, alongside a portable HEPA air cleaner in each occupied room.
What is Caledon's PM2.5 today?
Check the hourly PM2.5 chart for the Brampton station, which covers the area that includes Caledon, in micrograms per cubic metre.
How often should I change my furnace filter in Caledon?
Every 60 to 90 days in normal conditions: late September, late December and late March in Filterbuy's filter calendar above. During smoke, check it often and replace it when it looks dark brown or black.
Glossary
AQHI (Air Quality Health Index): Canada's official 1 to 10+ air quality scale, based on ozone, PM2.5 and nitrogen dioxide.
AQI (Air Quality Index): The U.S. EPA's 0 to 500 air quality scale, calculated differently from the AQHI.
PM2.5 (fine particulate matter): Airborne particles 2.5 micrometres or smaller, from sources such as smoke and exhaust.
Ground-level ozone (O3): A gas formed when sunlight reacts with other pollutants, peaking on hot afternoons.
Nitrogen dioxide (NO2): A gas released mainly when fuel is burned, including in vehicle engines.
MERV (Minimum Efficiency Reporting Value): A rating of how well an air filter captures particles from 0.3 to 10 microns.
Air Quality Ontario: The Ontario environment ministry's website for AQHI readings and station data.
ECCC (Environment and Climate Change Canada): The federal department behind AQHI forecasts and air quality alerts.
Brampton monitoring station: The Air Quality Ontario station at 109 McLaughlin Road South, the closest to Caledon.
HEPA (high-efficiency particulate air): A filter standard for portable air cleaners, not for home furnace slots.
CADR (clean air delivery rate): How much filtered air a portable air cleaner delivers.
Greenbelt: Ontario's protected farmland and natural areas, covering more than 75 per cent of Caledon.
Breathe Easier in Caledon
In Bolton, Caledon Village and everywhere between, a fresh Filterbuy filter is an easy way to improve the air inside your home, with free shipping to Canada on every order and prices in CAD.
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