Manchester Air Quality in Summer
Across 2019–2025, Manchester's summer (June–August) air quality had a median AQI of 40 (Good) over 644 monitored days in the Manchester-Nashua, NH area. 1.4% of summer days (9 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 79.5% of days. The cleanest summer on record here was 2019 (median AQI 39, 0 days above 100) and the worst was 2025 (median 44, 4 days above 100, peak AQI 123).
- Good: 78.7%
- Moderate: 19.9%
- Unhealthy for Sensitive Groups: 1.4%
- Unhealthy or worse: 0.0%
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How is the air in Manchester in summer?
Good on a typical day: median AQI 40 across 2019–2025, with 1.4% of summer days above AQI 100. Ground-level ozone is the main driver.
- ✓78.7% of summer days were Good (AQI 0–50), 19.9% Moderate (51–100).
- ✓9 days of 644 reached AQI 101+; the summer peak was 144.
- ✓Cleanest month: August; worst month: July.
Frequently asked questions
What is the air quality like in Manchester in summer?▾
Across 2019–2025, the median daily AQI in Manchester in summer was 40 (Good). 78.7% of days were Good, 19.9% Moderate, and 1.4% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Manchester?▾
A typical summer day in Manchester sits in the Good range (median AQI 40), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 71 of summer days (1.4%) reached AQI 101+ in 2019–2025.
Which pollutant causes Manchester's summer air quality problems?▾
Ground-level ozone set the daily AQI on 79.5% of summer days in Manchester. The highest summer AQI recorded in 2019–2025 was 144 (Unhealthy for Sensitive Groups), in 2025.
Manchester summer air quality, year by year
Manchester summer air quality by year (Manchester-Nashua, NH, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 92 | 39 | 0 | 80 | O3 |
| 2020 | 92 | 39 | 0 | 90 | O3 |
| 2021 | 92 | 39 | 2 | 144 | O3 |
| 2022 | 92 | 41 | 0 | 100 | O3 |
| 2023 | 92 | 40 | 3 | 109 | O3 |
| 2024 | 92 | 41 | 0 | 84 | O3 |
| 2025worst | 92 | 44 | 4 | 123 | O3 |
What summer air means in Manchester
A typical summer day in Manchester sits in the Good range (median AQI 40), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 71 of summer days (1.4%) reached AQI 101+ in 2019–2025.
Summer's median AQI of 40 is in line with Manchester's whole-year median of 37, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Manchester runs below the national Summer norm; 1.4% of its Summer days topped AQI 100 versus 3.6% nationally (below average).
Within the season, August is the cleanest month (median AQI 38, 0.9% of days above 100) and July the worst (median 41, 1.8% above 100).
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 season 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.