Stay updated with real-time air quality in Portsmouth, New Hampshire featuring accurate data on AQI, PM2.5, PM10, O3, NO2, SO2, and CO levels. Use our interactive map and detailed forecasts to monitor pollution trends, manage health risks, and plan your daily activities with confidence.
Live AQI (Air Quality Index)
39
Good
Portsmouth, New Hampshire
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
3.61 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
11.53 μg/m³
0
55
155
255
425
605+
41.85 ppb
0
55
71
86
201
201+
0.79 ppb
0
36
76
186
605
1005+
3.20 ppb
0
54
101
361
1250
2050+
0.14 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Portsmouth, New Hampshire
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AQI 39
Good
3.64μg/m³
PM2.5
12.06μg/m³
PM10
41.80ppb
O3
0.79ppb
SO2
3.20ppb
NO2
0.14ppm
CO
AQI 38
Good
4.38μg/m³
PM2.5
21.90μg/m³
PM10
40.67ppb
O3
0.73ppb
SO2
3.15ppb
NO2
0.14ppm
CO
AQI 38
Good
7.09μg/m³
PM2.5
21.39μg/m³
PM10
39.00ppb
O3
0.64ppb
SO2
3.15ppb
NO2
0.13ppm
CO
AQI 49
Good
8.55μg/m³
PM2.5
22.48μg/m³
PM10
38.84ppb
O3
0.63ppb
SO2
3.09ppb
NO2
0.14ppm
CO
AQI 36
Good
6.35μg/m³
PM2.5
28.04μg/m³
PM10
38.87ppb
O3
0.63ppb
SO2
3.18ppb
NO2
0.14ppm
CO
AQI 44
Good
7.56μg/m³
PM2.5
28.69μg/m³
PM10
38.32ppb
O3
0.57ppb
SO2
2.96ppb
NO2
0.13ppm
CO
Air quality and pollutant data for New Hampshire, USA are sourced from ground-based monitors and satellites, adhering to US EPA standards. Machine learning and advanced algorithms enhance the data by incorporating local variables like traffic and population density, ensuring high accuracy and dependability.
Source: Ambee Data Sources
The air quality information for Portsmouth, New Hampshire is updated every hour for accuracy.
In the past 24 hours, the air quality in Portsmouth, New Hampshire was at its worst at 06:00:00 on 2026-03-11.
In the last 24 hours, the best air quality in Portsmouth, New Hampshire was observed at 11:00:00 on 2026-03-11.
As of now, the AQI in Portsmouth, New Hampshire is 39, indicating Good conditions.
Portsmouth, New Hampshire air has the highest levels of O3.
Poor air quality in Portsmouth, New Hampshire means it's advisable to stay indoors and wear a mask for your protection.
PM2.5 levels in Portsmouth, New Hampshire are currently 3.606 μg/m3.
The PM10 concentration in Portsmouth, New Hampshire is 11.531 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Portsmouth, New Hampshire is 0.136 ppm.
Currently, Portsmouth, New Hampshire has a sulfur dioxide (SO2) concentration of 0.794 ppb.
The current ozone (O3) level in Portsmouth, New Hampshire at the moment is 41.855 ppm.
Nitrogen dioxide (NO2) level in Portsmouth, New Hampshire at the moment is 3.199 ppb.
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