Manchester Air Quality in Winter
Across 2019–2025, Manchester's winter (December–February) air quality had a median AQI of 36 (Good) over 632 monitored days in the Manchester-Nashua, NH area. 0.0% of winter days (0 of 632) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 84.7% of days. The cleanest winter on record here was 2023 (median AQI 33, 0 days above 100) and the worst was 2022 (median 39, 0 days above 100, peak AQI 55).
- Good: 95.7%
- Moderate: 4.3%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Manchester in winter?
Good on a typical day: median AQI 36 across 2019–2025, with 0.0% of winter days above AQI 100. Ground-level ozone is the main driver.
- ✓95.7% of winter days were Good (AQI 0–50), 4.3% Moderate (51–100).
- ✓0 days of 632 reached AQI 101+; the winter peak was 66.
- ✓Cleanest month: December; worst month: February.
Frequently asked questions
What is the air quality like in Manchester in winter?▾
Across 2019–2025, the median daily AQI in Manchester in winter was 36 (Good). 95.7% of days were Good, 4.3% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Manchester?▾
A typical winter day in Manchester sits in the Good range (median AQI 36), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of winter days reached AQI 101+ in 2019–2025.
Which pollutant causes Manchester's winter air quality problems?▾
Ground-level ozone set the daily AQI on 84.7% of winter days in Manchester. The highest winter AQI recorded in 2019–2025 was 66 (Moderate), in 2022.
Manchester winter air quality, year by year
Manchester winter air quality by year (Manchester-Nashua, NH, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 90 | 37 | 0 | 57 | O3 |
| 2020 | 91 | 34 | 0 | 52 | O3 |
| 2021 | 90 | 36 | 0 | 66 | O3 |
| 2022worst | 90 | 39 | 0 | 55 | O3 |
| 2023cleanest | 90 | 33 | 0 | 51 | O3 |
| 2024 | 91 | 33 | 0 | 52 | O3 |
| 2025 | 90 | 37 | 0 | 62 | O3 |
What winter air means in Manchester
A typical winter day in Manchester sits in the Good range (median AQI 36), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of winter days reached AQI 101+ in 2019–2025.
Winter's median AQI of 36 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 Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Manchester runs below the national Winter norm; 0.0% of its Winter days topped AQI 100 versus 0.6% nationally (about the same).
Within the season, December is the cleanest month (median AQI 33, 0.0% of days above 100) and February the worst (median 39, 0.0% 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.