Insights: Houston-The Woodlands-Sugar Land, TX metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 63 over 365 measured days in 2025, which corresponds to a Moderate band and a Very Poor metro-wide health grade. The monitored-day split lands at 37 Good days (10%), 282 Moderate (77%), and 35 Unhealthy-for-Sensitive-Groups (10%). The 90th-percentile AQI finished at 112 while the highest single-day reading hit 179 (Unhealthy). Metro residents averaged roughly 3.0 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -17.2 points and the median AQI moved +6 points, which classifies the multi-year trajectory as worsening. The annual record contains 11 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Metros with comparable AQI profiles include El Centro, CA (27.7% good, AQI 64); Visalia-Porterville, CA (24.1% good, AQI 64); Albuquerque, NM (24.9% good, AQI 61).