Manchester Air Quality in 2019
In 2019, Manchester's air quality (Manchester-Nashua, NH area) had a median daily AQI of 37 (Good) across 365 monitored days. 0 days (0.0%) reached Unhealthy for Sensitive Groups or worse, 345 were Good, and the year's peak AQI was 80 (Moderate). Ground-level ozone set the daily AQI on 337 of those days. The cleanest month of 2019 was September (median AQI 30, 0 days above 100) and the worst was March (median 44, 0 days above 100, peak 58).
- Good: 94.5%
- Moderate: 5.5%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Manchester
Today's main pollutant in Manchester is ground-level ozone (AQI 26). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
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How was Manchester's air quality in 2019?
Good on a typical day: median AQI 37, with 0 days above AQI 100 out of 365 monitored — the 1st cleanest of 7 years on record for the area.
- ✓Peak AQI in 2019: 80 (Moderate).
- ✓Ground-level ozone was the main pollutant on 337 days.
- ✓Cleanest month: September; worst: March.
Frequently asked questions
What was the average AQI in Manchester in 2019?▾
EPA's Air Quality System puts Manchester's (Manchester-Nashua, NH) median daily AQI for 2019 at 37, which is Good. 0 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 80.
Which month had the worst air quality in Manchester in 2019?▾
The cleanest month of 2019 was September (median AQI 30, 0 days above 100) and the worst was March (median 44, 0 days above 100, peak 58).
Was 2019 a good or bad year for Manchester's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 1st cleanest by days above AQI 100 — the best year on record here. 2019's median of 37 is in line with the area's typical annual median of 37.
Manchester month by month in 2019
Manchester air quality month by month, 2019 (Manchester-Nashua, NH, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 37 | 0 | 41 | O3 |
| February | 28 | 41 | 0 | 57 | O3 |
| Marchworst | 31 | 44 | 0 | 58 | O3 |
| April | 30 | 43 | 0 | 51 | O3 |
| May | 31 | 38 | 0 | 49 | O3 |
| June | 30 | 39 | 0 | 80 | O3 |
| July | 31 | 39 | 0 | 57 | O3 |
| August | 31 | 39 | 0 | 55 | O3 |
| Septembercleanest | 30 | 30 | 0 | 74 | O3 |
| October | 31 | 31 | 0 | 39 | O3 |
| November | 30 | 32 | 0 | 45 | O3 |
| December | 31 | 35 | 0 | 53 | O3 |
How 2019 compares
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 1st cleanest by days above AQI 100 — the best year on record here.
2019's median of 37 is in line with the area's typical annual median of 37.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Manchester
The latest EPA AirNow observation puts Manchester's AQI at 26 (O3). The figures above are multi-year annual statistics, not today's reading.
View current Manchester air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Manchester-Nashua, NH), 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.