Manchester Air Quality in August
Across 2019–2025, Manchester's August air quality had a median AQI of 38 (Good) over 217 monitored days in the Manchester-Nashua, NH area. 0.9% of August days (2 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 78.8% of days. The cleanest August on record here was 2021 (median AQI 35, 0 days above 100) and the worst was 2025 (median 45, 2 days above 100, peak AQI 105).
- Good: 82.0%
- Moderate: 17.1%
- Unhealthy for Sensitive Groups: 0.9%
- Unhealthy or worse: 0.0%
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How is the air in Manchester in August?
Good on a typical day: median AQI 38 across 2019–2025, with 0.9% of August days above AQI 100. Ground-level ozone is the main driver.
- ✓82.0% of August days were Good (AQI 0–50), 17.1% Moderate (51–100).
- ✓2 days of 217 reached AQI 101+; the August peak was 105.
- ✓Best August: 2021; worst August: 2025.
Frequently asked questions
What is the air quality like in Manchester in August?▾
Across 2019–2025, the median daily AQI in Manchester in August was 38 (Good). 82.0% of days were Good, 17.1% Moderate, and 0.9% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Manchester?▾
A typical August day in Manchester sits in the Good range (median AQI 38), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of August days reached AQI 101+ in 2019–2025.
Which pollutant causes Manchester's August air quality problems?▾
Ground-level ozone set the daily AQI on 78.8% of August days in Manchester. The highest August AQI recorded in 2019–2025 was 105 (Unhealthy for Sensitive Groups), in 2025.
Manchester August air quality, year by year
Manchester August air quality by year (Manchester-Nashua, NH, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 39 | 0 | 55 | O3 |
| 2020 | 31 | 37 | 0 | 90 | O3 |
| 2021cleanest | 31 | 35 | 0 | 64 | O3 |
| 2022 | 31 | 42 | 0 | 90 | O3 |
| 2023 | 31 | 35 | 0 | 63 | O3 |
| 2024 | 31 | 38 | 0 | 68 | O3 |
| 2025worst | 31 | 45 | 2 | 105 | O3 |
What August air means in Manchester
A typical August day in Manchester sits in the Good range (median AQI 38), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of August days reached AQI 101+ in 2019–2025.
August's median AQI of 38 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 August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Manchester runs below the national August norm; 0.9% of its August days topped AQI 100 versus 3.5% nationally (below average).
August is part of Manchester's summer season (June, July, August); the summer page pools all three months.
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 month 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.