24Earth live environment tool
Air Quality Checker
Check the latest outdoor air-quality measurements near a city or your current location. Results come from nearby monitoring stations and may not represent conditions across the whole area.
Monitor lookup
Check the air near you
Search a place or enter latitude and longitude. We prefer a recent stationary reference monitor, then the closest supported location available.
No location selected
Start with a monitor, not an assumption
Air can change across a city and through the day. A result is meaningful only when its station and observation time travel with the number.
The checker names the AQI system used. Concentrations and AQI are not interchangeable.
Air-quality data unavailable
Nearest recent observations
Air quality near your search
Monitor-level results for the selected location.
U.S. AQI unavailable
Latest air-quality index
Dominant pollutant—
- 0–50Good
- 51–100Moderate
- 101–150Unhealthy for sensitive groups
- 151–200Unhealthy
- 201–300Very unhealthy
- 301+Hazardous
Monitor readings
Latest pollutant concentrations
Each card retains its source-reported unit and observation time. Different pollutants may update at different hours.
Fine particles
Particles no wider than 2.5 micrometres.
No recent measurement from this monitor.
Inhalable particles
Particles no wider than 10 micrometres.
No recent measurement from this monitor.
Ground-level ozone
A reactive gas formed by pollutants in sunlight.
No recent measurement from this monitor.
Nitrogen dioxide
A combustion-related gas often elevated near roads.
No recent measurement from this monitor.
History
Recent measurements
Gaps remain visible. Lines do not imply measurements between missing observations.
Measurement history
Select a location to load recent observations.
Historical air-quality chart
No historical series has been loaded.
Historical observations will appear after a successful lookup.
View historical data table
| Local period | UTC period | Value | Unit | Coverage / status |
|---|---|---|---|---|
| No historical observations loaded. | ||||
Methodology and provenance
A nearby measurement, with its limits intact
This checker uses OpenAQ to find measurements shared by providers around the world. It applies the current U.S. EPA particle NowCast method only when the required hourly PM data and units are available; AirNow remains the authoritative public-facing source for reported North American NowCast AQI. Availability, instruments, units, reporting intervals, and validation practices vary by station.
AQI is named
The result identifies the U.S. EPA scale and distinguishes a provider NowCast from a 24Earth estimate. No supported method means no AQI.
Units stay visible
Concentrations retain their reported unit unless a documented conversion is applied. A concentration is not itself an AQI value.
Distance is approximate
Monitor distance is straight-line distance from the searched point. Local topography, traffic, smoke, and weather can make nearby conditions differ.
Definitions, timing, and health context
“Current” is time-bounded
The measurement time—not the moment the page loads—determines recency. Delayed observations are labeled as delayed; readings older than the current-data window are presented as historical rather than current.
Pollutant clocks can differ
Each pollutant card carries its own time. An AQI may use an averaging window, while a concentration card may show a provider-reported hourly observation.
Guidance is general
Health suggestions follow the displayed AQI category and dominant pollutant where available. They do not replace alerts from local authorities or advice from a health professional.
Missing is not zero
An unavailable station, pollutant, time window, or AQI calculation is shown as unavailable. The checker never substitutes a zero reading.
Data may be preliminary, delayed, unavailable, or subject to revision. AirNow observations are intended for timely public reporting and are not the fully validated regulatory record. OpenAQ coverage reflects data made publicly available by its contributing providers.
