How Clarity implements AQI calculations on OpenMap.
Clarity’s OpenMap is a publicly available way to view PM2.5 and Air Quality Index (AQI) data from Clarity devices and government reference monitors in one place.
Find out how to add your data to Clarity OpenMap in this article.
Air Quality Indices can be calculated in a variety of ways, and methods often vary country to country. On OpenMap we are using the following AQIs:
| Data From |
Hourly Data (daily or weekly plots) |
Daily Data (monthly or annual plots) |
| Clarity Nodes | PM2.5 NowCast AQI | 24-hour mean AQI |
| Reference Monitors |
For hourly data from Clarity Nodes and Reference Monitors, we display the PM2.5 NowCast AQI. The NowCast AQI is an index developed by the US Environmental Protection Agency (US EPA) to estimate air quality conditions during a given hour, using a weighted-average of the past several hours of pollutant concentration data. The exact number of hours used is dependent on the variability of concentrations. More of the recent data is used when concentrations are very stable, and less is used when concentrations are changing quickly, such as during wildfires or other air quality events. You can read more about EPA’s NowCast methodology here.
For daily data from Clarity Nodes and Reference Monitors, visible when viewing monthly or annual plots, we are displaying PM2.5 24-hour mean AQI, calculated using PM2.5 24-hour mean concentration according to this standard.Data from the government reference network is being added to OpenMap through three sources: the AirNow, the European Environment Agency (EEA) and OpenAQ.