Individuals who breathe polluted air can experience health effects within a few hours or days. The District measures pollutant concentrations in the local ambient (outdoor) air and uses historical data to predict pollutant levels in the future.
Air Quality Trends
The District determines the effectiveness of air quality regulations using the results of monitoring data over time. Rising pollution levels generally indicate that more controls are necessary, whereas a drop in pollution levels demonstrate that existing controls are successfully reducing emissions. This information is incorporated into air quality planning.
The District’s Air Quality Trends Report takes a look at monitored ambient air concentrations of criteria pollutants over time as well as emissions from key sources.
View the interactive storyboard of the most recent trends in the District. Previous reports on air quality trends (2014 and 2020) are attached below.
Air Quality Forecasts
The District is attaining the national ambient air quality standards (NAAQS) for all pollutants except ground-level ozone. Ground-level ozone, also known as smog, is created by a chemical reaction between precursor pollutants, primarily oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence of sunlight and high temperatures. “Ozone season” lasts from May to September. During ozone season, air quality forecasters rate the quality of the air on a daily basis and recommend actions when predictions indicate that air quality may be bad for public health.
- Learn about Healthy Air Actions that you can take today.
Mobile Community Air Monitoring Pilot Project
DOEE partnered with air quality and climate tech leader Aclima to launch an air quality monitoring pilot program in three priority communities. This project provides block-by-block information, on air pollution in these communities.
“Village Green” Park Bench Monitors
In 2026 DOEE installed four air quality park bench monitors in overburdened sections of the District. The new monitors joined the original pilot bench located within the National Zoo.
These solar-powered park bench monitors were developed by the EPA as a unique way to engage the public in measuring air quality and weather. They provide near real-time, reliable readings on levels of fine particle pollution, ozone, and black and brown carbon, as well as meteorological data. Learn more and see the data.
Fine Particulate Matter (PM2.5) in the District
In response to community requests, the Air Quality Division is posting near real-time PM2.5 data collected at each of its five federally-compliant PM2.5 monitoring stations. Read More>>
DCA Airplane Noise Assessment Project 
The DCA Airplane Noise Assessment Project was initiated by DOEE to investigate noise impacts to District residents from aircraft noise pollution.
Air Quality Data Sets
You can access data collected by the Air Quality Division on opendata.dc.gov and several other locations as follows:
- Realtime FRM/FEM Air Quality Data
- Historic FRM/FEM Air Quality Data
- DOEE Purple Air Sensor Data
- DOEE Clarity Node Data
Purple Air Sensor Loan Program
DOEE is working to better track localized particulate matter air pollution in local neighborhoods by involving residents in the PurpleAir sensor project. Learn more.
Clarity Node Sensor Network
DOEE has also deployed several dozen Clarity nodes throughout the District. In addition to PM2.5, these nodes can also measure NO2, CO, Ozone, and wind. These solar-powered sensors are deployed at host sites including libraries, public charter schools, universities, and businesses. In combination with our other monitors and sensors, the Clarity node network will help DOEE improve our awareness of hyper-local air quality for multiple key criteria air pollutants.
Visit the map of our current Clarity Node network.
Additional Sensor Testing
DOEE periodically tests other sensors to see what other capabilities would enable us to achieve additional air quality awareness and improvements. Examples include sensors that can measure VOCs, Black Carbon, and ultrafine particulates.
