Air quality in United States
Air quality in New Hampshire today
Updated
Good: average US AQI 45 across 8 cities in New Hampshire Worst now: Salem, NH (62); cleanest: Portsmouth, NH (31).
Live US AQI, PM2.5 and ozone for cities across New Hampshire, compared with the United States average.
- Average US AQI
- 45 Good
- United States average
- 48 747 cities
- Most polluted now
- Salem, NH AQI 62
- Cleanest now
- Portsmouth, NH AQI 31
- Cities above 100
- 0
Air quality in New Hampshire today
Right now the modelled air quality in New Hampshire averages a US AQI of 45 (Good) across the 8 cities we track. By category: 4 Good, 4 Moderate (of 8).
That is close to the United States average of 48, ranking 32 of 51 states from cleanest to most polluted.
Salem, NH has the worst air at 62 (PM2.5 2.9 µg/m³), and Portsmouth, NH the cleanest at 31. No tracked city is above 100, so no group needs to change plans.
New Hampshire cities by AQI (most polluted first)
| City | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Salem | 62 | Moderate | 2.9 | 3 | 85 |
| Derry | 62 | Moderate | 2.9 | 3 | 85 |
| Manchester | 52 | Moderate | 1.8 | 2 | 91 |
| Bedford | 52 | Moderate | 1.8 | 2 | 91 |
| Concord | 36 | Good | 1.4 | 1 | 88 |
| Dover | 31 | Good | 3.5 | 4 | 75 |
| Rochester | 31 | Good | 3.5 | 4 | 75 |
| Portsmouth | 31 | Good | 3.5 | 4 | 75 |
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Modelled by CAMS (Copernicus) via Open-Meteo, refreshed twice a day; read hour by hour from the forecast.
Cities in New Hampshire
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Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).