Indicator · us-good-air-days
Days with good air
AQI 50 or below, counties with a monitor reading at least 180 days.
- Unit
- % of days
- Places
- 916 counties in 2025
- Built from
- Yearly air quality summary by county
- Reading it
- Higher is better.
Map and compare every county on visualizedata.org →
Median county, 1980–2025
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Show the data as a table
Highest and lowest in 2025
| Carbon County, WY | 100.0% of days |
|---|---|
| Karnes County, TX | 100.0% of days |
| Martin County, NC | 100.0% of days |
| Sonoma County, CA | 100.0% of days |
| Uinta County, WY | 100.0% of days |
6 counties share this value; five are shown, alphabetically.
| Maricopa County, AZ | 8.8% of days |
|---|---|
| Riverside County, CA | 10.7% of days |
| Los Angeles County, CA | 10.7% of days |
| Harris County, TX | 11.0% of days |
| San Bernardino County, CA | 12.6% of days |
How it is computed
EPA good days / days with an AQI, from the Yearly air quality summary by county dataset on this site. visualizedata.org computes the indicator for every place and year; the full table, the map and each place's history are on its page there. The underlying data, with its source and license, is on the dataset page, with the API and downloads.