Hourly Weather | Today Saturday, December 27, 2025
Portland, Maine
3 AM
Cloudy Weather
18°
Feels Like
7
Humidity: 64%
Wind: 8 mph
UV Index: 0
4 AM
Cloudy Weather
18°
Feels Like
7
Humidity: 64%
Wind: 8 mph
UV Index: 0
5 AM
Cloudy Weather
18°
Feels Like
7
Humidity: 63%
Wind: 8 mph
UV Index: 0
6 AM
Cloudy Weather
18°
Feels Like
5
Humidity: 64%
Wind: 9 mph
UV Index: 0
7 AM
Cloudy Weather
18°
Feels Like
0
Humidity: 64%
Wind: 9 mph
UV Index: 0
8 AM
Cloudy Weather
18°
Feels Like
0
Humidity: 65%
Wind: 10 mph
UV Index: 0
9 AM
Cloudy Weather
18°
Feels Like
0
Humidity: 62%
Wind: 10 mph
UV Index: 1
10 AM
Cloudy Weather
18°
Feels Like
0
Humidity: 59%
Wind: 12 mph
UV Index: 1
11 AM
Cloudy Weather
19°
Feels Like
0
Humidity: 55%
Wind: 12 mph
UV Index: 1
12 PM
Cloudy Weather
21°
Feels Like 10°
0
Humidity: 53%
Wind: 10 mph
UV Index: 1
1 PM
Cloudy Weather
21°
Feels Like 10°
0
Humidity: 51%
Wind: 10 mph
UV Index: 1
2 PM
Cloudy Weather
21°
Feels Like 12°
0
Humidity: 50%
Wind: 10 mph
UV Index: 1
3 PM
Cloudy Weather
21°
Feels Like 12°
0
Humidity: 49%
Wind: 10 mph
UV Index: 1
4 PM
Cloudy Weather
21°
Feels Like 10°
0
Humidity: 53%
Wind: 9 mph
UV Index: 0
5 PM
Night
19°
Feels Like 12°
0
Humidity: 55%
Wind: 8 mph
UV Index: 0
6 PM
Night
19°
Feels Like 12°
0
Humidity: 58%
Wind: 7 mph
UV Index: 0
7 PM
Cloudy Night
19°
Feels Like 12°
0
Humidity: 60%
Wind: 7 mph
UV Index: 0
8 PM
Cloudy Night
19°
Feels Like 12°
0
Humidity: 59%
Wind: 7 mph
UV Index: 0
9 PM
Cloudy Night
19°
Feels Like 12°
0
Humidity: 59%
Wind: 8 mph
UV Index: 0
10 PM
Cloudy Night
19°
Feels Like 10°
0
Humidity: 60%
Wind: 8 mph
UV Index: 0
11 PM
Cloudy Night
19°
Feels Like 10°
0
Humidity: 59%
Wind: 8 mph
UV Index: 0

Hourly Air Quality Forecast - AQI (US EPA)

3 AM
32 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.29 µg/m³
  • PM10: 1.66 µg/m³
  • O3: 0.034 ppm
  • NO2: 3 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

4 AM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.09 µg/m³
  • PM10: 1.4 µg/m³
  • O3: 0.035 ppm
  • NO2: 2.5 ppb
  • SO2: 0.3 ppb
  • CO: 0.14 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

5 AM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.98 µg/m³
  • PM10: 1.22 µg/m³
  • O3: 0.036 ppm
  • NO2: 2.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.13 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

6 AM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 0.93 µg/m³
  • PM10: 1.21 µg/m³
  • O3: 0.036 ppm
  • NO2: 2.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.13 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

7 AM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.1 µg/m³
  • PM10: 1.46 µg/m³
  • O3: 0.036 ppm
  • NO2: 2.8 ppb
  • SO2: 0.3 ppb
  • CO: 0.14 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

8 AM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.31 µg/m³
  • PM10: 1.81 µg/m³
  • O3: 0.035 ppm
  • NO2: 3.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

9 AM
32 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.48 µg/m³
  • PM10: 2.11 µg/m³
  • O3: 0.035 ppm
  • NO2: 4.1 ppb
  • SO2: 0.4 ppb
  • CO: 0.15 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

10 AM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.61 µg/m³
  • PM10: 2.34 µg/m³
  • O3: 0.035 ppm
  • NO2: 4.2 ppb
  • SO2: 0.4 ppb
  • CO: 0.15 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

11 AM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.8 µg/m³
  • PM10: 2.67 µg/m³
  • O3: 0.036 ppm
  • NO2: 3.8 ppb
  • SO2: 0.5 ppb
  • CO: 0.15 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

12 PM
34 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.07 µg/m³
  • PM10: 3.05 µg/m³
  • O3: 0.036 ppm
  • NO2: 3.6 ppb
  • SO2: 0.5 ppb
  • CO: 0.15 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

1 PM
34 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.39 µg/m³
  • PM10: 3.43 µg/m³
  • O3: 0.037 ppm
  • NO2: 3.7 ppb
  • SO2: 0.5 ppb
  • CO: 0.15 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

2 PM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.11 µg/m³
  • PM10: 4.38 µg/m³
  • O3: 0.036 ppm
  • NO2: 4.8 ppb
  • SO2: 0.6 ppb
  • CO: 0.17 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

3 PM
30 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 4.12 µg/m³
  • PM10: 5.77 µg/m³
  • O3: 0.033 ppm
  • NO2: 7.4 ppb
  • SO2: 0.6 ppb
  • CO: 0.19 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

4 PM
26 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 5.01 µg/m³
  • PM10: 7.03 µg/m³
  • O3: 0.028 ppm
  • NO2: 11.5 ppb
  • SO2: 0.7 ppb
  • CO: 0.21 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

5 PM
25 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 5.96 µg/m³
  • PM10: 8.38 µg/m³
  • O3: 0.023 ppm
  • NO2: 16 ppb
  • SO2: 0.7 ppb
  • CO: 0.24 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

6 PM
31 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 7.41 µg/m³
  • PM10: 10.31 µg/m³
  • O3: 0.017 ppm
  • NO2: 20.1 ppb
  • SO2: 0.7 ppb
  • CO: 0.28 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

7 PM
39 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 9.34 µg/m³
  • PM10: 12.87 µg/m³
  • O3: 0.013 ppm
  • NO2: 23.6 ppb
  • SO2: 0.7 ppb
  • CO: 0.31 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

8 PM
46 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 11.12 µg/m³
  • PM10: 15.15 µg/m³
  • O3: 0.010 ppm
  • NO2: 25.5 ppb
  • SO2: 0.6 ppb
  • CO: 0.34 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

9 PM
50 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 12.12 µg/m³
  • PM10: 16.29 µg/m³
  • O3: 0.010 ppm
  • NO2: 25.4 ppb
  • SO2: 0.6 ppb
  • CO: 0.34 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

10 PM
51 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 12.26 µg/m³
  • PM10: 16.27 µg/m³
  • O3: 0.011 ppm
  • NO2: 23.6 ppb
  • SO2: 0.5 ppb
  • CO: 0.34 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

11 PM
46 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 11.04 µg/m³
  • PM10: 14.45 µg/m³
  • O3: 0.014 ppm
  • NO2: 20 ppb
  • SO2: 0.5 ppb
  • CO: 0.31 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.