Hourly Weather | Today Wednesday, April 29, 2026
Portland, Maine
4 AM
Cloudy Weather
43°
Feels Like 37°
3
Humidity: 89%
UV Index: 0
Wind: 8 mph
5 AM
Cloudy Weather
43°
Feels Like 37°
4
Humidity: 89%
UV Index: 0
Wind: 8 mph
6 AM
Cloudy Weather
43°
Feels Like 37°
4
Humidity: 91%
UV Index: 0
Wind: 8 mph
7 AM
Cloudy Weather
43°
Feels Like 37°
7
Humidity: 92%
UV Index: 0
Wind: 8 mph
8 AM
Cloudy Weather
43°
Feels Like 37°
14
Humidity: 93%
UV Index: 0
Wind: 9 mph
9 AM
Cloudy Weather
45°
Feels Like 39°
14
Humidity: 92%
UV Index: 1
Wind: 9 mph
10 AM
Cloudy Weather
45°
Feels Like 39°
18
Humidity: 93%
UV Index: 1
Wind: 10 mph
11 AM
Cloudy Weather
45°
Feels Like 39°
49
Humidity: 92%
UV Index: 1
Wind: 10 mph
12 PM
Rainy Weather
45°
Feels Like 37°
55
Humidity: 91%
UV Index: 1
Wind: 12 mph
1 PM
Rainy Weather
46°
Feels Like 39°
55
Humidity: 89%
UV Index: 2
Wind: 12 mph
2 PM
Cloudy Weather
45°
Feels Like 39°
40
Humidity: 92%
UV Index: 2
Wind: 12 mph
3 PM
Cloudy Weather
45°
Feels Like 39°
34
Humidity: 93%
UV Index: 1
Wind: 12 mph
4 PM
Cloudy Weather
45°
Feels Like 37°
38
Humidity: 97%
UV Index: 1
Wind: 12 mph
5 PM
Cloudy Weather
45°
Feels Like 37°
49
Humidity: 98%
UV Index: 1
Wind: 12 mph
6 PM
Rainy Weather
43°
Feels Like 34°
55
Humidity: 100%
UV Index: 0
Wind: 12 mph
7 PM
Rainy Weather
45°
Feels Like 34°
55
Humidity: 99%
UV Index: 0
Wind: 12 mph
8 PM
Cloudy Weather
43°
Feels Like 36°
40
Humidity: 100%
UV Index: 0
Wind: 10 mph
9 PM
Cloudy Weather
43°
Feels Like 36°
34
Humidity: 100%
UV Index: 0
Wind: 10 mph
10 PM
Cloudy Weather
45°
Feels Like 37°
37
Humidity: 100%
UV Index: 0
Wind: 10 mph
11 PM
Cloudy Weather
45°
Feels Like 37°
43
Humidity: 100%
UV Index: 0
Wind: 10 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 2.01 µg/m³
  • PM10: 3.78 µg/m³
  • O3: 0.042 ppm
  • NO2: 2.2 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.97 µg/m³
  • PM10: 3.62 µg/m³
  • O3: 0.041 ppm
  • NO2: 2.1 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.94 µg/m³
  • PM10: 3.44 µg/m³
  • O3: 0.041 ppm
  • NO2: 2.1 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.98 µg/m³
  • PM10: 3.4 µg/m³
  • O3: 0.041 ppm
  • NO2: 2.7 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 AM
38 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.03 µg/m³
  • PM10: 3.37 µg/m³
  • O3: 0.041 ppm
  • NO2: 3.4 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
39 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.98 µg/m³
  • PM10: 3.12 µg/m³
  • O3: 0.042 ppm
  • NO2: 3.5 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.93 µg/m³
  • PM10: 2.9 µg/m³
  • O3: 0.044 ppm
  • NO2: 3.2 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.94 µg/m³
  • PM10: 2.85 µg/m³
  • O3: 0.046 ppm
  • NO2: 2.7 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.01 µg/m³
  • PM10: 2.93 µg/m³
  • O3: 0.048 ppm
  • NO2: 2.3 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.09 µg/m³
  • PM10: 3.03 µg/m³
  • O3: 0.050 ppm
  • NO2: 2 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.19 µg/m³
  • PM10: 3.17 µg/m³
  • O3: 0.052 ppm
  • NO2: 1.8 ppb
  • SO2: 0.4 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.31 µg/m³
  • PM10: 3.29 µg/m³
  • O3: 0.052 ppm
  • NO2: 1.9 ppb
  • SO2: 0.4 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.4 µg/m³
  • PM10: 3.33 µg/m³
  • O3: 0.051 ppm
  • NO2: 2.3 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 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: 2.45 µg/m³
  • PM10: 3.32 µg/m³
  • O3: 0.050 ppm
  • NO2: 2.9 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.57 µg/m³
  • PM10: 3.42 µg/m³
  • O3: 0.049 ppm
  • NO2: 3.7 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.82 µg/m³
  • PM10: 3.76 µg/m³
  • O3: 0.048 ppm
  • NO2: 4.1 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
44 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.17 µg/m³
  • PM10: 4.32 µg/m³
  • O3: 0.048 ppm
  • NO2: 4.1 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 PM
44 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.5 µg/m³
  • PM10: 4.81 µg/m³
  • O3: 0.048 ppm
  • NO2: 3.7 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.8 µg/m³
  • PM10: 5.37 µg/m³
  • O3: 0.048 ppm
  • NO2: 3.2 ppb
  • SO2: 0.3 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.07 µg/m³
  • PM10: 6.15 µg/m³
  • O3: 0.049 ppm
  • NO2: 2.9 ppb
  • SO2: 0.3 ppb
  • CO: 0.13 ppm

Health Recommendations:

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