DIY live map of Air quality in the US

I’d never heard of Airnow; do you know if that’s where Apple and Google Maps get their AQI data too? I like seeing some points spill over to Canada… nice hint of the international cooperation… https://www.airnow.gov/partners/canadian-partners/

Given the news today I wanted to see how quickly one can find live air quality data and create a DIY map. Using Observable Plot.