Checking my logs from the CZU Fire Complex back in 2020, the AQI at my house in the SF Peninsula topped out at 766. It was pretty bad.
""" On June 7th, 2023, 4:12:06 PM PDT 10 Minute Average US EPA PM2.5 AQI is now 320 Sensor: Bill Nye the AQI """ https://map.purpleair.com/1/m/i/mAQI/a10/p604800/cC0?select=...