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)
56
Moderate
Portsmouth, New Hampshire
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
12.26 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
23.05 μg/m³
0
55
155
255
425
605+
28.01 ppb
0
55
71
86
201
201+
1.19 ppb
0
36
76
186
605
1005+
2.15 ppb
0
54
101
361
1250
2050+
0.12 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Portsmouth, New Hampshire
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AQI 56
Moderate
12.09μg/m³
PM2.5
23.18μg/m³
PM10
24.39ppb
O3
0.51ppb
SO2
3.33ppb
NO2
0.12ppm
CO
AQI 56
Moderate
11.78μg/m³
PM2.5
24.27μg/m³
PM10
26.24ppb
O3
0.59ppb
SO2
3.48ppb
NO2
0.12ppm
CO
AQI 54
Moderate
11.18μg/m³
PM2.5
28.14μg/m³
PM10
25.08ppb
O3
0.68ppb
SO2
3.25ppb
NO2
0.12ppm
CO
AQI 56
Moderate
12.03μg/m³
PM2.5
25.68μg/m³
PM10
28.65ppb
O3
0.69ppb
SO2
2.31ppb
NO2
0.12ppm
CO
AQI 54
Moderate
11.09μg/m³
PM2.5
29.57μg/m³
PM10
25.27ppb
O3
0.69ppb
SO2
3.36ppb
NO2
0.12ppm
CO
AQI 54
Moderate
11.05μg/m³
PM2.5
35.02μg/m³
PM10
29.24ppb
O3
0.73ppb
SO2
2.36ppb
NO2
0.12ppm
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 03:00:00 on 2026-06-29.
In the last 24 hours, the best air quality in Portsmouth, New Hampshire was observed at 01:00:00 on 2026-06-29.
As of now, the AQI in Portsmouth, New Hampshire is 56, indicating Moderate 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 12.256 μg/m3.
The PM10 concentration in Portsmouth, New Hampshire is 23.048 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Portsmouth, New Hampshire is 0.122 ppm.
Currently, Portsmouth, New Hampshire has a sulfur dioxide (SO2) concentration of 1.19 ppb.
The current ozone (O3) level in Portsmouth, New Hampshire at the moment is 28.014 ppm.
Nitrogen dioxide (NO2) level in Portsmouth, New Hampshire at the moment is 2.15 ppb.
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