Score
Clean Air
Composite clean-air score from EPA county AQI days, PM2.5, and ozone monitor summaries.
Higher values rank better for this score.
How It's Calculated
The latest published score is normalized to a 0-100 scale. The method below explains what the score rewards, with technical source metadata available for audit.
How the ranking is built
Clean Air combines EPA county AQI days, annual PM2.5, and ozone monitor summaries into one lower-pollution score.
- 1
Each pollution burden is inverse percentile-rank normalized over the full scored location distribution.
- 2
The final composite is 30% low 90th percentile AQI, 20% low non-good days, 15% low unhealthy days, 20% low PM2.5, and 15% low ozone.
- 3
County monitor data is preferred
- 4
missing county metrics fall back to state and then national averages with lower confidence.
Technical details
Read from the current master score table for this criterion.
The top 10 below ignore your blended relocation weights and sort only by Clean Air.
What This Score Means
Clean Air combines EPA county AQI days, annual PM2.5, and ozone monitor summaries into one lower-pollution score.
Statistics Feeding This Score
- 90th percentile AQISource: EPA AirData
County annual 90th percentile AQI from daily AQI summaries.
- Non-good AQI daysSource: EPA AirData
Share of AQI days that were moderate or worse.
- Unhealthy AQI daysSource: EPA AirData
Share of AQI days that were unhealthy for sensitive groups or worse.
- PM2.5 and ozone monitor summariesSource: EPA AirData
Annual PM2.5 mean and 8-hour ozone 4th maximum from county monitors.
Source Data
Known Limits
- EPA AirData is county and monitor based, not a parcel-level exposure model.
- Counties without monitor data use state or national fallback values with lower confidence.
- Annual summaries can miss neighborhood-scale roads, wildfire smoke episodes, indoor filtration, wind patterns, and short-term seasonal variation.
Top 10 Locations
Ranked by Clean Air.