Real-Time Air Quality: PM2.5 in NYC

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This page contains visualizations. If you are using a screenreader, you can download a CSV file of the last 7 days of realtime air quality data.

Fine particles (PM2.5) are among the most harmful pollutants. Long-term exposure to PM2.5 contributes to an estimated 2,000 excess deaths from lung and heart disease each year in NYC (1 out of every 25 deaths in NYC), and short-term exposure contributes to asthma incidents severe enough to require a trip to the emergency department, and other health threats.

The air quality in NYC is generally good and has been improving over time. For PM2.5, NYC meets the National Ambient Air Quality Standard of an annual average under 12 μg/m3, and a 24-hour average under 35 μg/m3.

But hour to hour, there is large variation in our air quality - even in neighborhoods with the cleanest air. PM2.5 levels can spike to levels that can harm health, especially for people sensitive to air pollution. These higher levels are driven by daily changes in traffic volume, weather patterns that can trap emissions, and other short-term events.

Explore real-time data on PM2.5 (fine particles) from our network of realtime air quality monitors around NYC.

About the data

Data are hourly measurements of PM2.5, in micrograms per cubic meter of air (µg/m3). External factors can sometimes affect monitor functioning. Data are preliminary and subject to change. Times are in Eastern Standard Time.

Street-level monitors

Data come from the NYC Community Air Survey's street-level monitors, which measure ground-level exposures. We apply a calibration factor to make our data comparable to DEC data and historical EPA data.

NYS DEC monitors

We show the average readings from 11 rooftop monitors from the NY State Department of Environmental Conservation (DEC), which collects data for the Federal Clean Air Act.

Download archived data.
Location Sort Last 24 hours (µg/m3)

Exceeds NAAQS 24-hour standard

All levels are below the NAAQS 24-hour standard (35 µg/m3)

*Monitor reported less than 18 hours in the last day.

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Hourly PM2.5 (in µg/m3) | NAAQS 24-hour PM2.5 standard (35 µg/m3)
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MAP

Last 24 hours:

LOCATION: the average PM2.5 at this location is XX. This is XX the 24-hour NAAQS standard of 35.

Last 24 hours

No value from the monitor. Sometimes monitors go down or have other problems. We only produce average values if there are more than 18 hourly readings over the last 24 hours.

The Air Quality Index

The Air Quality Index is the US Environmental Protection Agency's way of reporting air quality. It reports whether any of five major pollutants (ground-level ozone, fine particles, carbon monoxide, sulfur dioxide and nitrogen dioxide) are at levels that can harm health.

Air quality varies because sources vary

In NYC, about 30% of PM2.5 comes from far-away sources like coal-burning power plants in the Midwest. But more than half comes from local sources.

Buildings

Building density affects a neighborhood's air quality because like vehicles, buildings burn fuel and emit pollutants: their boilers burn oil and gas to produce heat and hot water. This is one reason we often see more air pollution in the winter. Because of new heating oil regulations, PM2.5 has gone down dramatically, and SO2 levels are now indetectable. Read more at the NYCCAS annual report.

Industrial area

Industrial areas affect a neighborhood's air quality because of diesel exhaust from trucks idling and traveling through industrial areas, and from industrial combustion equipment.

Traffic

Traffic density affects a neighborhood's air quality because engines produce PM2.5, black carbon, and NOx. While electric vehicles help reduce emissions, all vehicles also contribute to PM2.5 through tire wear and braking. Traffic volume is one reason we often see daily spikes in PM2.5 concentration in the mornings and evenings.

Trucks

Truck traffic density affects a neighborhood's air quality because diesel combustion produces additional pollutants.

Common patterns in the data

There are several patterns that commonly show up in the data from our air quality monitors. Look at recent data for patterns that indicate:

Spatial differences

The monitors are in neighborhoods with different emissions sources, so have different PM2.5 levels. Midtown, which has the highest traffic density, usually has the most PM2.5.

Daily spikes

PM2.5 levels usually rise in the morning as traffic volume increases. These temporal differences (time spikes) are usually greater than spatial differences (the differences between neighborhoods). It's very rare for these spikes to exceed the National Ambient Air Quality Standard of 35 μg/m3 for 24 hours.

Weather patterns

Weather can trap emissions and cause PM2.5 to build up. Sometimes we see a clear west-to-east pattern in rising PM2.5, as weather patterns moving into NYC traps local emissions. Other times, weather can bring wildfire smoke from far-away fires.

Other spikes

Sometimes there are dramatic, short-term spikes at unexpected times, and without having a camera on each monitor, we don't know what causes them. However, they can be explained by something as simple as a truck idling for a few minutes underneath the monitor.

To download data, choose the month, year, and data format (JSON or CSV) below.

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This URL format can be used to access any available month of data, by specifying the year, month, and format.

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Site info: This file contains information about the SiteID field in the data files.

About the data: Data in this archive are hourly averaged measurements of PM2.5 from the New York City Community Air Survey’s network of TSI DustTrak sensors. Different sensor technologies will result in different readings; we apply a correction factor to raw data, based on environmental factors, to better match federal regulatory sensors.

Measurements: The value shown is PM2.5 in micrograms per cubic meter of air (µg/m3). ObservationTimeUTC datetime stamp displayed is the beginning of the averaged PM2.5 measurements for the hour (e.g. 2/1/2020 1:00:00 AM (UTC) reflects data collected between 2/1/2020 1:00:00 AM (UTC) and 2/1/2020 1:59:00 AM (UTC)).

External factors can sometimes affect monitor functioning. Data are preliminary and subject to change.

Change Log:

  • 6/10/2024: Updated correction factor applied to all current and historical data. Data downloaded before this date may differ slightly from data downloaded after this date.