EPA AirData
2023-2025 annual summaries; files refreshed June 25, 2026- Data
- EPA annual PM2.5 concentration-by-monitor summaries for both annual mean and annual 98th-percentile daily concentration, retaining observed exceptional-event conditions and excluding superseded uncorrected T640/T640X methods.
- What it tells us
- Blends up to three monitoring sites near each named community's representative point. Distance, completeness, and explicit state or national fallback confidence limit what sparse monitoring can imply.