Ah, the forum software linked me to this thread: How to Calculate the US EPA PM2.5 AQI
which answered the question. That is, the pm2.5 value reported by the API is a raw number, and needs to be converted to the value used by the EPA and shown on the map. No problem.
Does this mean that the JSON data retrieved directly from the sensor is already appropriately converted? It’s a curious difference. Did I miss a page that clarifies which values are raw and which are EPA-adjusted?
Thanks!
David