Hourly Weather | Today Thursday, July 23, 2026
Portland, Maine
5 AM
Cloudy Night
63°
Feels Like 61°
0
Humidity: 76%
UV Index: 0
Wind: 6 mph
6 AM
Cloudy Weather
61°
Feels Like 61°
0
Humidity: 78%
UV Index: 0
Wind: 6 mph
7 AM
Cloudy Weather
63°
Feels Like 63°
0
Humidity: 74%
UV Index: 1
Wind: 7 mph
8 AM
Sunny Weather
64°
Feels Like 66°
0
Humidity: 68%
UV Index: 2
Wind: 7 mph
9 AM
Sunny Weather
68°
Feels Like 70°
0
Humidity: 61%
UV Index: 3
Wind: 7 mph
10 AM
Sunny Weather
70°
Feels Like 73°
0
Humidity: 54%
UV Index: 5
Wind: 7 mph
11 AM
Cloudy Weather
72°
Feels Like 79°
0
Humidity: 49%
UV Index: 6
Wind: 8 mph
12 PM
Cloudy Weather
73°
Feels Like 81°
0
Humidity: 46%
UV Index: 8
Wind: 8 mph
1 PM
Cloudy Weather
75°
Feels Like 81°
0
Humidity: 46%
UV Index: 9
Wind: 9 mph
2 PM
Cloudy Weather
75°
Feels Like 82°
0
Humidity: 44%
UV Index: 8
Wind: 9 mph
3 PM
Cloudy Weather
75°
Feels Like 79°
0
Humidity: 47%
UV Index: 6
Wind: 9 mph
4 PM
Cloudy Weather
73°
Feels Like 75°
0
Humidity: 49%
UV Index: 5
Wind: 10 mph
5 PM
Cloudy Weather
73°
Feels Like 73°
0
Humidity: 51%
UV Index: 3
Wind: 10 mph
6 PM
Cloudy Weather
72°
Feels Like 72°
0
Humidity: 53%
UV Index: 2
Wind: 10 mph
7 PM
Cloudy Weather
70°
Feels Like 68°
0
Humidity: 58%
UV Index: 1
Wind: 9 mph
8 PM
Sunny Weather
66°
Feels Like 64°
0
Humidity: 65%
UV Index: 0
Wind: 8 mph
9 PM
Night
64°
Feels Like 63°
0
Humidity: 71%
UV Index: 0
Wind: 8 mph
10 PM
Night
63°
Feels Like 61°
0
Humidity: 79%
UV Index: 0
Wind: 7 mph
11 PM
Night
61°
Feels Like 59°
0
Humidity: 81%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 0.79 µg/m³
  • PM10: 0.99 µg/m³
  • O3: 0.020 ppm
  • NO2: 2 ppb
  • SO2: 0.3 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.7 µg/m³
  • PM10: 0.92 µg/m³
  • O3: 0.018 ppm
  • NO2: 2.1 ppb
  • SO2: 0.3 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.65 µg/m³
  • PM10: 0.89 µg/m³
  • O3: 0.017 ppm
  • NO2: 2.5 ppb
  • SO2: 0.3 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.59 µg/m³
  • PM10: 0.83 µg/m³
  • O3: 0.019 ppm
  • NO2: 2.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.5 µg/m³
  • PM10: 0.61 µg/m³
  • O3: 0.026 ppm
  • NO2: 1.9 ppb
  • SO2: 0.4 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.51 µg/m³
  • PM10: 0.66 µg/m³
  • O3: 0.030 ppm
  • NO2: 1.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.75 µg/m³
  • PM10: 0.91 µg/m³
  • O3: 0.035 ppm
  • NO2: 1.3 ppb
  • SO2: 0.4 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.9 µg/m³
  • PM10: 1.06 µg/m³
  • O3: 0.044 ppm
  • NO2: 0.8 ppb
  • SO2: 0.3 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.99 µg/m³
  • PM10: 1.16 µg/m³
  • O3: 0.049 ppm
  • NO2: 0.7 ppb
  • SO2: 0.2 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.12 µg/m³
  • PM10: 1.31 µg/m³
  • O3: 0.050 ppm
  • NO2: 0.7 ppb
  • SO2: 0.2 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.26 µg/m³
  • PM10: 1.48 µg/m³
  • O3: 0.051 ppm
  • NO2: 0.7 ppb
  • SO2: 0.3 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.41 µg/m³
  • PM10: 1.65 µg/m³
  • O3: 0.051 ppm
  • NO2: 0.8 ppb
  • SO2: 0.3 ppb
  • CO: 0.08 ppm

Health Recommendations:

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

5 PM
47 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.54 µg/m³
  • PM10: 1.8 µg/m³
  • O3: 0.051 ppm
  • NO2: 1 ppb
  • SO2: 0.3 ppb
  • CO: 0.09 ppm

Health Recommendations:

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

6 PM
43 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.03 µg/m³
  • PM10: 2.36 µg/m³
  • O3: 0.046 ppm
  • NO2: 3.4 ppb
  • SO2: 0.4 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

7 PM
36 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.73 µg/m³
  • PM10: 3.18 µg/m³
  • O3: 0.039 ppm
  • NO2: 7 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

8 PM
31 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.26 µg/m³
  • PM10: 3.83 µg/m³
  • O3: 0.034 ppm
  • NO2: 9.8 ppb
  • SO2: 0.5 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

9 PM
28 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.58 µg/m³
  • PM10: 4.21 µg/m³
  • O3: 0.031 ppm
  • NO2: 10.4 ppb
  • SO2: 0.5 ppb
  • CO: 0.16 ppm

Health Recommendations:

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

10 PM
27 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.83 µg/m³
  • PM10: 4.51 µg/m³
  • O3: 0.029 ppm
  • NO2: 10.2 ppb
  • SO2: 0.5 ppb
  • CO: 0.16 ppm

Health Recommendations:

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

11 PM
25 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 4.12 µg/m³
  • PM10: 4.83 µg/m³
  • O3: 0.027 ppm
  • NO2: 9.9 ppb
  • SO2: 0.5 ppb
  • CO: 0.16 ppm

Health Recommendations:

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