Air Quality

An overview of our A2AQ air quality monitoring network and the Idling Reduction Ordinance.

Current AQI Map

The below map from Clarity Movement shows the current Air Quality Index (AQI) at each of our monitoring stations in Ann Arbor. To sign up for alerts when AQI reaches the Unhealthy (AQI 4) level, select the monitoring station of interest and then click the bell icon next to the station name. Scroll down to learn more about AQI.

Explore Our Air Quality Data

All of the data gathered by our network of Clarity air quality monitors is publicly available and can be viewed using the buttons to the right.

If the above map doesn't load, click the "A2AQ Map" button to view the map of the current Air Quality Index (AQI) at each of our monitoring stations in Ann Arbor.

Click the "AQ Dashboard" button to explore our data in more depth. This dashboard includes a graph of daily AQI data over time, as well as graphs of each individual pollutant's concentration over time.

Click the "Data Download" button to download a CSV file of all the data our monitoring stations have collected since the first one was installed in June of 2022.

Click the "AirNow Fire & Smoke Map" button to visit the official PM2.5 pollution map of the US EPA and USDA Forest Service, which includes data provided by our network of Clarity monitoring stations.

A2AQ Map AQ Dashboard Data Download AirNow Fire & Smoke Map

Overview

Clean, healthy air is critical to ensuring our health and community vitality. Research has linked air pollutants such as ozone and particulate matter to lung and heart disease, increased asthma rates, and other health problems. In our community, the major sources of these air pollutants include emissions from internal combustion engines (i.e., tailpipe emissions from cars), emissions from power plants, and emissions from indoor and outdoor appliances that run on fuels such as natural gas, diesel, propane, and gasoline. In addition, climate change is negatively impacting air quality by causing more extreme heat days, which both drives up cooling needs (and power plant emissions) and creates the conditions for the formation of ground level ozone. Climate change is also leading to more wildfires and the associated increase in particulate matter. Learn more about the impacts of climate change on air quality from the Fourth National Climate Assessment.

Air Quality in Ann Arbor

In order to monitor our community's ambient air quality, OSI has installed a network of 10 air quality monitors across the city, as displayed on Clarity's A2AQ ("Ann Arbor Air Quality") Map.

These solar-powered air quality monitors measure pollutants such as fine particulate matter (PM2.5), nitrogen dioxide (NO₂), and ozone (O₃). These pollutants, when at high enough concentrations, can have negative impacts on both human health and the environment.

Concentrations of these pollutants can be used to calculate the Air Quality Index (AQI), which is the air quality reporting index used by the United States EPA. AQI values are calculated using the individual concentrations of five major pollutants (ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide), with the pollutant at the highest concentration determining the value of the AQI. AQI values range from 0 to 500, with higher values representing greater levels of air pollution. These values are divided into six different levels of AQI (an AQI of 1, for example, corresponds to AQI values between 0-50 and is considered "good" air quality, while an AQI of 6 corresponds to AQI values above 301 and is considered "hazardous."). See the below table from the EPA for a visualization of the different AQI levels. To learn more about AQI and what the different levels may mean for your health, visit the EPA's AQI Basics and Activity Guides webpages.

By monitoring AQI, we can be alerted to potentially harmful concentrations of air pollutants and gather data on the potential sources of those high concentrations.

Learn More About...

Did you know that vehicle idling constitutes 1.6% of all U.S. greenhouse gas emissions, double the total emissions from the steel and iron manufacturing in the country? This is partly why, effective July 1, 2017, Ann Arbor has an Idling Reduction Ordinance. This ordinance specifies that:

Commercial vehicles have a 5-minute idling limit city-wide and no idling while vehicles are unoccupied.
Non-commercial vehicles have a 5-minute idling limit in signed "No Idling" zones and no idling while vehicles are unoccupied.

*The ordinance does not impact cars on residential property or in driveways.

For violations of the ordinance, citations can be issued. If you observe a violation of the ordinance, please immediately report the violation by contacting Community Standards at 734-794-6942 or dispatch at 734-994-2911, so that an officer may be sent to the site to confirm the violation.

Do Your Part

1. Turn your engine off. Whether you're picking up your child from school or using the ATM, turn off your engine if you're stopped for longer than ten seconds.

2. Reduce warm-up idling. Experts agree modern engines require only a short idle period after engine start—even in very cold temperatures. Driving slowly for the first mile or two is the best way for the car to warm up. Long idling periods can harm your engine and waste gas.

3. Spread the word. Most people idle out of habit. Encourage your family, friends, and neighbors to help protect children's and environmental health, as well as save money, by turning off their vehicles.

Frequent testing of indoor air and water quality is important to our health and safety. For more information on how to test for air and water pollutants - as well as other dangerous substances - in your home, check out this guide from the Safety, Health, and Consumer Council and SafeHome.org. The Ann Arbor District Library has air quality sensors in their lending library - check one out today to measure the air quality in your home!

A key piece of A²ZERO (Strategy 2) focuses on mass electrification of buildings, appliances, and vehicles. This work is designed to improve indoor air quality, comfort, and safety, all while reducing local and regional greenhouse gas emissions. If you're interested in learning more about the City's efforts to electrify, please click here.

Contact Info

Sean Reynolds

Senior Analyst, Office of Sustainability & Innovations

Email Sean