Now that most people don’t feel the need to wear masks indoors, we’re starting to wear masks outdoors — because of air quality problems, many of which are being caused by this year’s raging forest fires in Canada. This first came to the attention of many people in early June when the skies on the East Coast temporarily turned a strange orange color. Now, many of us are not only checking in the morning to see if it will rain but whether it’s safe to go on a run or to take the kids to the park. The acronym AQI (for Air Quality Index) is quickly becoming as familiar as the term covid-19 became three years earlier.
As a result of all this, you may want to become more aware of the AQI in your particular area to monitor whether you should, for example, be careful about doing a morning run or, if you have a sensitivity, whether you should be going out at all.
There are a variety of apps out there that you can use to monitor local AQI, and we’ve listed a few of them below, together with each app’s user interface, available features, and premium features (if any).
While the apps differ in a variety of ways — such as where they get their data, how much information they supply, and whether they market their own sensors — they do have at least one thing in common: they use color-coded AQI ratings to help guide you as to the health of the air around you. Most tend to follow the EPA’s index, as shown in this chart, which appears on the AirNow.gov site:
Basically, it goes like that: green means you’re good to go; yellow means that if you’re especially sensitive, you may want to put off that run; orange means people with sensitivities should probably stay indoors; red means more people could experience issues and most people should at least be careful; purple means everyone is at risk, and maroon means — well, it means we’re in an emergency situation.
So, can you trust what the apps are telling you? To be honest, it’s nearly impossible to test which offers the most trustworthy data — there are just too many factors involved. The accuracy of the rating not only depends on when and where the reading is being taken but also on the sensitivity and location of the sensor(s) and the algorithms being used to put together all the data. As a result, at any single point in time, you can get different readings from different apps — although they should be approximately in the same ballpark.
In the following list, then, we simply offer each app’s description of where it gets its data from. Sources can include official and non-official sources or a combination of both. An app can use government monitoring agencies as collected by the EPA and other state, local, and trivial agencies. It can also access information from networks of privately owned sensors that pick up local air quality data and send the info to a central collection point such as PurpleAir or one managed by the app itself.
In the end, these are only guidelines. How you use them depends on your specific needs.
The official air quality app from the EPA, AirNow, gives you the current AQI rating at your location using an easy-to-read dial, along with a forecast for the next couple of days. Tap a small details button on the dial (look closely — it’s easy to miss), and you get information about which pollutant is more in evidence.
You can check several different regions, access a map that shows where any trouble spots are, or look at another map that specifically tracks smoke, along with satellite info about any significant fires.
AirNow doesn’t offer that many extra features — but on the other hand, you’re getting the data directly from the source.
Where does it get its data? “IQ Air Visual Air Quality Measurements are collected by state, local or tribal monitoring agencies using federal reference or equivalent monitoring methods approved by EPA.” More information is available here.
IQAir uses both government info and its own network of devices, which it sells to individuals. In fact, the main screen has two tabs: one labeled Places, which shows the current ratings in specific areas, and one labeled Devices, so you can see the readings from your own air quality sensors. (IQAir sells sensors and other things, such as masks and air purifiers). The Places page will let you know which independent devices, if any, were contributing data — for example, on my page, it said that the data was provided by “1 anonymous contributor.” I tapped on that and was told that the contributor was part of the PurpleAir network.
The main screen uses the usual color scheme to give immediate feedback, including the current AQI and the level of PM2.5 particles. You also get the current weather, a three-day forecast and a seven-day forecast. Further down, you can see the current stats for other areas; you can decide which cities you’d like to monitor.
An interesting Exposure feature lets you set your home and work locations and shows what you are exposed to in each of those and outdoors, hour by hour. Another option lets you see how other cities are doing around the world and gives access to any current news stories.
Where does it get its data? “AirVisual’s unique real-time AI-based (Artificial Intelligence) system collects, analyses and validates millions of air quality data points which come mostly from ground-based air quality monitors operated by governments, non-governmental organizations and individuals.” More information is available here.
Plume Labs is another company that offers both information on air quality and the chance to participate in its networks. The app offers hour-to-hour color-coded info on its initial page, together with the current AQI readings and a forecast for the next three days — all above an ad for its air quality monitor. Tap on the readings, though, and you get a much more detailed information screen with the ratings for a variety of pollutants. You can also choose to either see the AQI as gathered by Plume’s network of devices or the EPA’s current readings (or those of several other countries).
Another interesting feature includes tips for how to handle the current air quality, depending on your level of activity; there are suggestions if you’re running, biking, sensitive, and picnicking. (For example, tap the running icon, and you get something like: “Outdoor activities: A run is still ok, but be careful!”).
Where does it get its data? “Plume Labs uses World Health Organization (WHO) guidelines as well as international standards developed by the United States Environmental Protection Agency (EPA) and other scientific studies to define the Plume AQI and its seven associated categories.” More information is available here.
AirCare takes a more social viewpoint of air quality; it allows you, for example, to take a photo of the current pollution outside and share it with your friends. But it also offers a great deal of data.
The top page shows you your air quality ratings, together with the pollen and UV index (which is handy); beneath that are ads. (There is a Pro version that removes the ads and offers homescreen widgets and Apple Watch support, among other things, for $39.99 a year or $5.99 a month.)
To get the full info, click on the small “details” button in the lower right corner of the air quality notice. Here, you’ll find color-coded ratings for a variety of pollutants; tap on each, and you’ll get a graph showing its ratings for the last 24 hours or (if you prefer) the last 12 hours and a prediction for the next 12 hours. A paid account lets you change that to the last / next 24 and 48 hours.
The page also tells you which data sources AirCare is using; in my case, it was pulling data from the European Space Agency and Purpleair.
Tabs at the bottom let you access a full map of your area that shows not only the AQI but also any fires, the wind directions, and the current UV. You can also access rankings for various countries, resources for learning about air quality, and ads for various air purifiers.
Where does it get its data? According to the FAQ, “AirCare is an aggregator of air quality data from many networks around the world, including government, volunteer, and satellite ones. We take all of this raw data and transform it into an AQI number via our intelligent algorithms.” More information is available here.
Breezometer (which was acquired by Google in late 2022) doesn’t assume that you are only interested in the AQI; in fact, during setup, it asks if there is any specific pollen count that you want to know about. You can choose from a variety of grasses, weeds, and trees.
The main page is nice and simple: it shows a color-coded half-circle that indicates the current AQI over a cartoon scene. You can tap on the Air Quality icon at the bottom of the screen to get more detailed information, including an hourly forecast and health tips for various categories of people, including children, elderly, pregnant, asthma, active, or heart patients. You can then scroll down the page for specifics on “What Am I Breathing Right Now,” which gives you the ratings for PM 2.5, PM 10, and a variety of other pollutants. Click on each pollutant for an explanation of what it is and what its effects are. Scroll down a bit further for a weather report.
Other icons at the bottom of the screen lead you to an air quality map and current pollen counts. A premium plan gets rid of all ads and offers a 12-hour air quality forecast for $11.99 a year or $2.99 a month. You can choose to get your data from a variety of sources, including the “BreezoMeter AQI,” US AQI, and those of several other countries.
Where does it get its data? According to the company, Breezometer gets its info from “multiple data layers including governmental monitoring stations, real-time traffic information, meteorological conditions, as well as CAMS data, combined with innovative technology in machine learning and big data analytics.” More information is available here.