AirNow API

EPA has updated the NowCast for ozone - the technical method used to show current ozone values on AirNow.gov and will be updating the code on AirNow.gov the evening of 8/1/19. Using this improved method, current ozone conditions will more closely represent the 8-hour average value for ozone air quality and should be more consistent with the daily AQI value.

For a technical paper describing this change and more information about the R code and example files, please visit https://github.com/USEPA/O3-Nowcast

Thank you,
EPA and AirNow Data Management Center.



The AirNow API replaces the previous AirNow Gateway web services. It includes file outputs and RSS data feeds. AirNow Gateway users can use their existing login information to access the new AirNow API web pages and web services. Access to the AirNow API is generally available to the public, and new accounts can be acquired via the Log In page. See the AirNow API Fact Sheet for more information.

The U.S. EPA AirNow program (www.AirNow.gov) protects public health by providing forecast and real-time observed air quality information across the United States, Canada, and Mexico. AirNow receives real-time air quality observations from over 2,000 monitoring stations and collects forecasts for more than 300 cities.

All data provided by AirNow API and AirNow Gateway are made possible by the efforts of more than 120 local, state, tribal, provincial, and federal government agencies (Participating Agencies). These data are not fully verified or validated and should be considered preliminary and subject to change. Data and information reported to AirNow are for the express purpose of reporting and forecasting the AQI. As such, they should not be used to formulate or support regulation, trends, guidance, or any other government or public decision making. Official regulatory air quality data must be obtained from EPA's Air Quality System (AQS or AirData).