New Haven Air Quality in 2019
In 2019, New Haven's air quality (New Haven-Milford, CT area) had a median daily AQI of 44 (Good) across 365 monitored days. 14 days (3.8%) reached Unhealthy for Sensitive Groups or worse, 228 were Good, and the year's peak AQI was 159 (Unhealthy). Ground-level ozone set the daily AQI on 181 of those days. The cleanest month of 2019 was October (median AQI 35, 0 days above 100) and the worst was July (median 67, 8 days above 100, peak 159).
- Good: 62.5%
- Moderate: 33.7%
- Unhealthy for Sensitive Groups: 3.3%
- Unhealthy or worse: 0.5%
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How was New Haven's air quality in 2019?
Good on a typical day: median AQI 44, with 14 days above AQI 100 out of 365 monitored — the 6th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2019: 159 (Unhealthy).
- ✓Ground-level ozone was the main pollutant on 181 days.
- ✓Cleanest month: October; worst: July.
Frequently asked questions
What was the average AQI in New Haven in 2019?▾
EPA's Air Quality System puts New Haven's (New Haven-Milford, CT) median daily AQI for 2019 at 44, which is Good. 14 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 159.
Which month had the worst air quality in New Haven in 2019?▾
The cleanest month of 2019 was October (median AQI 35, 0 days above 100) and the worst was July (median 67, 8 days above 100, peak 159).
Was 2019 a good or bad year for New Haven's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 6th cleanest by days above AQI 100. 2019's median of 44 is in line with the area's typical annual median of 44.
New Haven month by month in 2019
New Haven air quality month by month, 2019 (New Haven-Milford, CT, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 40 | 0 | 65 | PM2.5 |
| February | 28 | 44 | 1 | 105 | PM2.5 |
| March | 31 | 49 | 0 | 86 | PM2.5 |
| April | 30 | 44 | 0 | 59 | O3 |
| May | 31 | 41 | 0 | 74 | O3 |
| June | 30 | 45 | 2 | 147 | O3 |
| Julyworst | 31 | 67 | 8 | 159 | O3 |
| August | 31 | 54 | 2 | 147 | O3 |
| September | 30 | 38 | 1 | 126 | O3 |
| Octobercleanest | 31 | 35 | 0 | 54 | PM2.5 |
| November | 30 | 42 | 0 | 73 | PM2.5 |
| December | 31 | 44 | 0 | 97 | PM2.5 |
How 2019 compares
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 6th cleanest by days above AQI 100.
2019's median of 44 is in line with the area's typical annual median of 44.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in New Haven
The latest EPA AirNow observation puts New Haven's AQI at 48 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current New Haven air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (New Haven-Milford, CT), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.