What Is the Air Quality in St Croix, Virgin Islands?

St Croix, Virgin Islands earns an A — it is among the cleanest U.S. cities tracked by EPA monitoring, with median AQI averaging just 27 over the past five years. Days in the "Good" category dominate the calendar; air-quality alerts are rare.

St Croix, Virgin Islands's 5-year median AQI of 27 is 14 points below the national average of 41 — meaningfully cleaner than the typical U.S. metro tracked here. Within Virgin Islands, St Croix, Virgin Islands runs more polluted than the state average of 24 — local sources or geography are concentrating pollution above the state's typical reading.

Air quality in St Croix, Virgin Islands has been improving over the past decade, with median AQI dropping by roughly 3.5 points per year. That is consistent with the broader national pattern — most U.S. metros have seen steady reductions in particulate and ozone pollution since the 2010s as cleaner vehicles and power plants come online.

In 2014, St Croix, Virgin Islands posted a median AQI of 52. By 2022 that figure was 29 — a drop of 23 AQI points cleaner across 9 years of EPA records.

Across the past five years, this area has logged just 0 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 0 days per year, or roughly one every other month. That is a low count by national standards.

For most healthy adults, current air quality in this area does not require any change in behavior. People with severe asthma, COPD, or recent cardiac events should still keep an eye on daily AQI alerts, especially during wildfire season. Because PM2.5 penetrates deep into the lungs and bloodstream, an N95 or KN95 mask provides meaningful protection on smoky or high-particulate days — surgical masks do not.