Manchester Air Quality in 2025
In 2025, Manchester's air quality (Manchester-Nashua, NH area) had a median daily AQI of 38 (Good) across 365 monitored days. 4 days (1.1%) reached Unhealthy for Sensitive Groups or worse, 310 were Good, and the year's peak AQI was 123 (Unhealthy for Sensitive Groups). Ground-level ozone set the daily AQI on 308 of those days. The cleanest month of 2025 was October (median AQI 31, 0 days above 100) and the worst was August (median 45, 2 days above 100, peak 105).
- Good: 84.9%
- Moderate: 14.0%
- Unhealthy for Sensitive Groups: 1.1%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
Even with good outdoor air in Manchester, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How was Manchester's air quality in 2025?
Good on a typical day: median AQI 38, with 4 days above AQI 100 out of 365 monitored — the 6th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2025: 123 (Unhealthy for Sensitive Groups).
- ✓Ground-level ozone was the main pollutant on 308 days.
- ✓Cleanest month: October; worst: August.
Frequently asked questions
What was the average AQI in Manchester in 2025?▾
EPA's Air Quality System puts Manchester's (Manchester-Nashua, NH) median daily AQI for 2025 at 38, which is Good. 4 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 123.
Which month had the worst air quality in Manchester in 2025?▾
The cleanest month of 2025 was October (median AQI 31, 0 days above 100) and the worst was August (median 45, 2 days above 100, peak 105).
Was 2025 a good or bad year for Manchester's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 6th cleanest by days above AQI 100. 2025's median of 38 is in line with the area's typical annual median of 37.
Manchester month by month in 2025
Manchester air quality month by month, 2025 (Manchester-Nashua, NH, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 35 | 0 | 55 | O3 |
| February | 28 | 38 | 0 | 62 | O3 |
| March | 31 | 42 | 0 | 61 | O3 |
| April | 30 | 44 | 0 | 84 | O3 |
| May | 31 | 37 | 0 | 61 | O3 |
| June | 30 | 46 | 1 | 101 | O3 |
| July | 31 | 43 | 1 | 123 | O3 |
| Augustworst | 31 | 45 | 2 | 105 | O3 |
| September | 30 | 36 | 0 | 58 | O3 |
| Octobercleanest | 31 | 31 | 0 | 100 | O3 |
| November | 30 | 31 | 0 | 37 | O3 |
| December | 31 | 36 | 0 | 47 | O3 |
How 2025 compares
Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 6th cleanest by days above AQI 100.
2025's median of 38 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 24 (PM2.5). 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.