Air Quality
Moderate
Air quality in Harris County is rated moderate with a median AQI of 63 (274 days measured in 2025).
Air Quality — Harris County (2025)i
AQSThe Air Quality Index measures how clean or polluted the air is on a given day. AQI is reported at the county level. A score of 0-50 is considered good; 51-100 is moderate; above 100 may be unhealthy for sensitive groups.
Median AQI
PM2.5 Daysi
172Ozone Daysi
81