Insights: Santa Cruz-Watsonville, CA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 37 over 181 measured days in 2025, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 148 Good days (82%), 33 Moderate (18%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 57 while the highest single-day reading hit 71 (Moderate). Metro residents averaged roughly 24.5 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, good days shifted by -113 and the median AQI moved -2 points, which classifies the multi-year trajectory as improving. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Athens, TN (77.5% good, AQI 37); Bemidji, MN (88.8% good, AQI 37); Chambersburg-Waynesboro, PA (93.0% good, AQI 37).