Good news — the EPA updated the air quality index on May 6th.
Good news: AQI now includes a wider range of conditions that make people sick.
Complicated news: since AQI is based on health impacts rather than an absolute measure of pollutants, anyone basing research or analysis on AQI should expect the definition of a one unit difference in AQI to change.
Time to update my own monitoring/early warning system
https://www.epa.gov/system/files/documents/2024-02/pm-naaqs-air-quality-index-fact-sheet.pdf