Tips for Using PurpleAir’s Free Air Quality Map

Free Air Quality Map by PurpleAir

Many countries and cities suffer from poor air quality, where people unknowingly inhale particulate matter (PM) concentrations higher than what’s recommended by experts.

But how can you check the air quality around you? By the time your eyes and nose notice air pollution, it can be too late—the damage has been done to your lungs. Instead, you need a real-time air quality map that you can check anytime.

In this blog, we explore how you can use our PurpleAir Map to monitor the air quality around you.

What is the PurpleAir Map?

The PurpleAir Map is a real-time, free air quality map that you can use to view the air quality of specific areas worldwide. The data we collect comes from PurpleAir air quality monitors and updates every two minutes.

Here are four things you can do in our PurpleAir air quality map: 

  1. Search for air quality monitors by zip code, address, or monitor name.
  2. Monitor the indoor and outdoor air quality in specific areas.
  3. Configure search results by data type, conversions or corrections, and averages over time.
  4. Download current map graph data for any data layer, conversion factor, and averaging period.

How to Use the PurpleAir Air Quality Map 

The easiest way to use the PurpleAir Map is by finding your location and clicking on the dots to see what air quality looks like in your area. But that’s only the tip of the iceberg, as the PurpleAir Map can give you more details on air quality.

Here are our top tips on getting the most out of our PurpleAir Map:

1. Adjust Data Layers

You can configure our air quality map to view specific information. Just click the gear icon, and the Configuration Menu will pop up.

 PurpleAir Air Quality Map

Here’s what each of those settings means: 

  • Data layer: This changes the data displayed on the map. You can choose different Air Quality Indexes (AQI), visibility data, environmental data, raw data, and metadata.
  • Apply conversion: If you choose the AQI data layer, you can filter further by applying conversion factors for different types of pollution with corresponding particle densities to more accurately display air quality.
  • Averaging period: PurpleAir air quality monitors take an average reading of the air quality and send the data to our servers once every two minutes, but you can choose averages to see trends over time.
  • Base map type: Change how the map looks by toggling among detailed, basic, satellite, topographic, dark, and auto.
  • Use accessible colors when available: Turn this setting on for accessibility needs, so the map marker colors are easier to see.
  • Show outside, inside, and personal sensors: Turn on to see the data from specific types of monitors. For example, if you only check “show outside,” only the outdoor air quality monitors will appear on the map.
  • Reporting or modified within: This field filters map markers that haven’t reported or been modified within a set range of time to our servers.
  • Show averages as rings: This setting will display thin rings around each map marker that represents its previous recent averages.
  • Show place names on top: Turn this on and you’ll see the names of countries, cities, roads, and more above device markers on the air quality map. It makes it easier for you to locate a specific area.

2. Change the AQI Scale

Change the Air Quality Index (AQI) to your area so the scores are according to your country’s standards. For example, there are data layers according to the State of Washington’s advisory and the Village Green Project. There are also layers for Canada, Australia, Europe, and Mexico.

By default, this air quality map uses the AQI of PM2.5 by default for the United States Environmental Protection Agency (US EPA). The US EPA AQI ranges from 0 to 500, split into different categories that indicate air quality based on particulate matter, one of the five major air pollutants. 

US Air quality index scale based on the EPA

3. Know the Different Map Markers

The PurpleAir Map displays PurpleAir air quality monitors as colored dots, known as map markers. Each map marker reports air quality information, indicated by their design.

Here’s how to understand them: 

Inside vs. Outside Air Quality 

Map markers indicate if the air quality monitor is tracking indoor or outdoor air quality. Those outlined in black denote indoor air quality monitors, while the absence of this outline signifies outdoor monitors.  

 Inside vs. outside air quality map marker

Proximity and Precision 

If two air quality monitors are close to each other, you may see overlapping map markers. To accurately view such closely situated monitors, simply zoom in on the map. If the map marker is grey, however, it means that the monitor is inactive. The number of grey markers will change depending on your “reporting and modified within” setting on the configuration page.

 Inactive monitors and overlapping PurpleAir monitors

Confidence in Data 

PurpleAir air quality monitors with two laser counters calculate a confidence score. When the confidence score is low, the map marker looks slightly transparent. When the confidence score is high, the map marker is of a solid color. A sensor's confidence score is based on the discrepancy between its two laser counters. The level of confidence corresponds with the trustworthiness of the monitor’s data.

 High vs. low confidence map markers

4. Save Your Map Settings

Once you have all the settings according to your preference, you can bookmark the URL on your browser. That way, you can revisit the map and have all your settings stay the same each time. After all, the more you check the air quality forecasts in your area, the better you can prepare for the future. 

If you’re using an Apple device, you can check this tutorial on YouTube to add the URL to your home screen. And if you would rather see the PurpleAir Map on your phone, you can create an app shortcut on your mobile device by following the instructions we provide in our FAQ.

5. Connect Your PurpleAir Monitor

All PurpleAir air quality monitors registered and connected to WiFi can appear on the map. The monitors registered as public will immediately and automatically show up, while monitors registered as private will require a custom link.  

If your monitors are private but you want to see them on the map, just log in to the PurpleAir Map and they will show up. We’ve detailed the steps in our guide for custom links and logging in. 

Worried About Air Quality? 

Monitor the Particulate Matter levels around the world with our free, real-time PurpleAir Map, or join PurpleAir’s mission to make air quality data accessible to everyone by investing in an air quality monitor for your home. Together, we can be informed and make changes in our daily habits and the community to improve air quality.