Data credits
Attribution and usage notes for third-party data behind the API.
FLASH products are built on our own models and processing, with some public and licensed inputs. The notices below are required or requested by those data providers.
Air quality observations
Observed AQI comes from U.S. federal, state, local and tribal air quality agencies through the U.S. EPA AirNow program. These observations are preliminary and unvalidated, may change, and are not for regulatory use. Official regulatory air quality data is available from the EPA Air Quality System (AQS).
Copernicus
Smoke and PM2.5 forecasts contain modified Copernicus Atmosphere Monitoring Service information 2026.
Worldwide alert climatology contains modified Copernicus Climate Change Service information 2026. Hersbach, H., et al. (2020). The ERA5 global reanalysis. QJRMS 146, 1999-2049, doi:10.1002/qj.3803, CC BY 4.0.
Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.
NOAA
Weather model, radar, satellite, alert and storm report data from NOAA and the National Weather Service are U.S. Government works in the public domain. Station climatology uses the Global Historical Climatology Network - Daily (GHCN-Daily), NOAA National Centers for Environmental Information. Use of NOAA data does not imply NOAA endorsement of FLASH products.