Bad Air Days in St Thomas, Virgin Islands
Not enough data
EPA monitors in St Thomas ran on too few days between 2016 and 2025 to give a fair yearly count (about 48% of days covered). Neighbouring counties below are a better guide.
What actually helps here
- EPA monitors here ran too few days to give a fair yearly count. Use AirNow for today's air.
The record for St Thomas
The worst recent year was 2018, with 1 bad day on 183 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2018-09-20 | 126 | PM2.5 |
| 2019-06-21 | 92 | PM2.5 |
| 2018-08-07 | 87 | PM2.5 |
| 2019-06-20 | 85 | PM2.5 |
| 2018-09-21 | 84 | PM2.5 |
The air on a normal day
Across 526 monitored days from 2018 to 2020, the air in St Thomas rated Good on 72% of them, close to the 72% typical of monitored counties, and Moderate on 28%. The median day sat at AQI 36; one day in ten went above 61.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)100%526 days
St Thomas by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2020 | 75 | 58 | 17 | 0 | 0 | 31 | 75 |
| 2019 | 268 | 195 | 73 | 0 | 0 | 37 | 92 |
| 2018 | 183 | 127 | 55 | 1 | 0 | 36 | 126 |
Elsewhere in Virgin Islands
How this is counted
A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day.