Air quality today
Readings come from public monitoring networks. Keyless coverage exists today for the United States (EPA AirNow) and Canada (ECCC AQHI).
Preliminary readings from official networks, not fully validated. For health decisions follow your doctor and your local environmental agency.
| Station | AQI | Category | Main pollutant |
|---|---|---|---|
| New York City | 29 | Good (0 to 50) | PM2.5 |
| Los Angeles | 51 | Moderate (51 to 100) | PM2.5 |
| Toronto | 25 | Good (0 to 50) | OZONE |
| Brooklyn | 29 | Good (0 to 50) | PM2.5 |
| Chicago | 38 | Good (0 to 50) | PM2.5 |
| Queens | 21 | Good (0 to 50) | OZONE |
| Houston | 65 | Moderate (51 to 100) | PM2.5 |
| Montréal | 24 | Good (0 to 50) | OZONE |
| Phoenix | 70 | Moderate (51 to 100) | PM10 |
| Philadelphia | 25 | Good (0 to 50) | OZONE |
| San Antonio | 55 | Moderate (51 to 100) | PM2.5 |
| Manhattan | 21 | Good (0 to 50) | OZONE |
Index
| Range | What to do |
|---|---|
| Good (0 to 50) | No health risk expected. |
| Moderate (51 to 100) | Unusually sensitive people may cut back on outdoor effort. |
| Unhealthy for sensitive groups (101 to 150) | Children, older adults and people with asthma or heart disease should reduce hard outdoor activity. |
| Unhealthy (151 to 200) | Everyone may feel effects; sensitive groups should stay indoors. |
| Very unhealthy (201 to 300) | Health alert: avoid outdoor exertion. |
| Hazardous (above 300) | Emergency conditions: stay in filtered air. |
Choose a city
- New York CityNew York, US
- Los AngelesCalifornia, US
- TorontoOntario, CA
- BrooklynNew York, US
- ChicagoIllinois, US
- QueensNew York, US
- HoustonTexas, US
- MontréalQuebec, CA
- PhoenixArizona, US
- PhiladelphiaPennsylvania, US
- San AntonioTexas, US
- ManhattanNew York, US
- San DiegoCalifornia, US
- The BronxNew York, US
- DallasTexas, US
- CalgaryAlberta, CA
- OttawaOntario, CA
- EdmontonAlberta, CA
- JacksonvilleFlorida, US
- Fort WorthTexas, US
- San JoseCalifornia, US
- AustinTexas, US
- ColumbusOhio, US
- CharlotteNorth Carolina, US
- IndianapolisIndiana, US
- San FranciscoCalifornia, US
- SeattleWashington, US
- WinnipegManitoba, CA
- DenverColorado, US
- MississaugaOntario, CA
- WashingtonDistrict of Columbia, US
- NashvilleTennessee, US
- Oklahoma CityOklahoma, US
- El PasoTexas, US
- VancouverBritish Columbia, CA
- BramptonOntario, CA
- BostonMassachusetts, US
- PortlandOregon, US
- DetroitMichigan, US
- Las VegasNevada, US
- New South MemphisTennessee, US
- MemphisTennessee, US
- LouisvilleKentucky, US
- BaltimoreMaryland, US
- South BostonMassachusetts, US
- HamiltonOntario, CA
- SurreyBritish Columbia, CA
- AlbuquerqueNew Mexico, US
- MilwaukeeWisconsin, US
- TucsonArizona, US
- FresnoCalifornia, US
- QuébecQuebec, CA
- SacramentoCalifornia, US
- AtlantaGeorgia, US
- MiamiFlorida, US
- OmahaNebraska, US
- RaleighNorth Carolina, US
- Kansas CityMissouri, US
- Long BeachCalifornia, US
- MesaArizona, US
Data from 10/15/26, 5:44 PM UTC
- U.S. EPA AirNow (áreas de referência, arquivo público)Licence: Dado público da EPA, sujeito às AirNow Data Use Guidelines (atribuição obrigatória) · Credit: U.S. EPA AirNow e a agência estadual, tribal ou local que fez a mediçãoDados preliminares, sem validação final; não servem para fins regulatórios.
- Environment and Climate Change Canada — AQHILicence: ECCC End-use Licence (uso livre com citação da fonte) · Credit: Environment and Climate Change Canada
- GeoNames cities15000Licence: CC BY 4.0 · Credit: Dados de cidades: GeoNames (CC BY 4.0)
- Dados de cidades: GeoNames (CC BY 4.0)
How to read these numbers
An air quality index turns the concentration of several pollutants into a single number, driven by whichever pollutant is worst at that moment. On most days that is fine particulate matter (PM2.5) or ozone.
Countries with no open public interface are shown here as "no open source". In those cases the route is the national agency site, linked on each region page, because we would rather not display third party data under a licence we could not verify.
Frequently asked questions
- What is a good air quality index?
- On the US scale, up to 50 is good and 51 to 100 is moderate. Above 100 it starts to affect sensitive groups. The Canadian scale is different: it runs from 1 to over 10.
- What exactly is PM2.5?
- Particles smaller than 2.5 micrometres across, fine enough to reach deep into the lung. They come from fuel burning, wildfires and agricultural fires.
- Does an air purifier help?
- A purifier with a HEPA filter cuts PM2.5 well inside a closed room, but does nothing for ozone. Closing windows on a smoke day and running a filter is what the EPA recommends.