Insights: Los Angeles-Long Beach-Anaheim, CA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 74 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 39 Good days (11%), 227 Moderate (62%), and 67 Unhealthy-for-Sensitive-Groups (18%). The 90th-percentile AQI finished at 147 while the highest single-day reading hit 201 (Very Unhealthy). Metro residents averaged roughly 3.2 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 +0.2 points (measured against 270 monitored days in 2020 and 297 in 2025, so raw day counts are not comparable) and the median AQI moved -11 points, which classifies the multi-year trajectory as improving. The annual record contains 32 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Metros with comparable AQI profiles include Bakersfield, CA (17.5% good, AQI 70); El Paso, TX (18.1% good, AQI 70); Phoenix-Mesa-Scottsdale, AZ (6.6% good, AQI 78).