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)
33
Good
Portsmouth, New Hampshire
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
6.32 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
11.04 μg/m³
0
55
155
255
425
605+
29.08 ppb
0
55
71
86
201
201+
0.90 ppb
0
36
76
186
605
1005+
3.32 ppb
0
54
101
361
1250
2050+
0.22 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Portsmouth, New Hampshire
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AQI 38
Good
6.90μg/m³
PM2.5
11.24μg/m³
PM10
29.10ppb
O3
0.89ppb
SO2
5.13ppb
NO2
0.22ppm
CO
AQI 38
Good
7.13μg/m³
PM2.5
15.87μg/m³
PM10
29.82ppb
O3
0.84ppb
SO2
5.20ppb
NO2
0.22ppm
CO
AQI 44
Good
7.74μg/m³
PM2.5
24.82μg/m³
PM10
30.46ppb
O3
0.77ppb
SO2
4.88ppb
NO2
0.22ppm
CO
AQI 44
Good
8.39μg/m³
PM2.5
25.49μg/m³
PM10
28.84ppb
O3
0.76ppb
SO2
4.84ppb
NO2
0.22ppm
CO
AQI 44
Good
8.45μg/m³
PM2.5
25.49μg/m³
PM10
30.54ppb
O3
0.80ppb
SO2
5.00ppb
NO2
0.22ppm
CO
AQI 44
Good
8.41μg/m³
PM2.5
25.46μg/m³
PM10
29.18ppb
O3
0.72ppb
SO2
4.24ppb
NO2
0.22ppm
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 05:00:00 on 2026-02-11.
In the last 24 hours, the best air quality in Portsmouth, New Hampshire was observed at 04:00:00 on 2026-02-11.
As of now, the AQI in Portsmouth, New Hampshire is 33, indicating Good conditions.
Portsmouth, New Hampshire air has the highest levels of PM2.5.
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 6.324 μg/m3.
The PM10 concentration in Portsmouth, New Hampshire is 11.043 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Portsmouth, New Hampshire is 0.222 ppm.
Currently, Portsmouth, New Hampshire has a sulfur dioxide (SO2) concentration of 0.896 ppb.
The current ozone (O3) level in Portsmouth, New Hampshire at the moment is 29.084 ppm.
Nitrogen dioxide (NO2) level in Portsmouth, New Hampshire at the moment is 3.319 ppb.
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