Hourly Weather | Today Thursday, February 26, 2026
Portland, Maine
4 AM
Cloudy Night
27°
Feels Like 19°
3
Frost Risk: 96%
Humidity: 96%
UV Index: 0
Wind: 8 mph
5 AM
Cloudy Night
28°
Feels Like 19°
3
Humidity: 88%
UV Index: 0
Wind: 9 mph
6 AM
Cloudy Night
28°
Feels Like 18°
2
Humidity: 78%
UV Index: 0
Wind: 10 mph
7 AM
Cloudy Weather
28°
Feels Like 18°
0
Humidity: 68%
UV Index: 0
Wind: 13 mph
8 AM
Cloudy Weather
30°
Feels Like 19°
0
Humidity: 60%
UV Index: 1
Wind: 14 mph
9 AM
Cloudy Weather
32°
Feels Like 21°
0
Humidity: 53%
UV Index: 2
Wind: 15 mph
10 AM
Cloudy Weather
34°
Feels Like 23°
0
Humidity: 48%
UV Index: 3
Wind: 15 mph
11 AM
Cloudy Weather
36°
Feels Like 27°
0
Humidity: 44%
UV Index: 3
Wind: 15 mph
12 PM
Cloudy Weather
36°
Feels Like 28°
0
Humidity: 42%
UV Index: 3
Wind: 16 mph
1 PM
Cloudy Weather
36°
Feels Like 27°
0
Humidity: 41%
UV Index: 3
Wind: 16 mph
2 PM
Cloudy Weather
37°
Feels Like 28°
0
Humidity: 39%
UV Index: 3
Wind: 16 mph
3 PM
Cloudy Weather
37°
Feels Like 27°
0
Humidity: 43%
UV Index: 2
Wind: 15 mph
4 PM
Cloudy Weather
36°
Feels Like 25°
0
Humidity: 46%
UV Index: 1
Wind: 14 mph
5 PM
Cloudy Weather
34°
Feels Like 21°
0
Humidity: 49%
UV Index: 0
Wind: 13 mph
6 PM
Cloudy Night
32°
Feels Like 21°
0
Humidity: 52%
UV Index: 0
Wind: 12 mph
7 PM
Cloudy Night
28°
Feels Like 21°
0
Humidity: 57%
UV Index: 0
Wind: 8 mph
8 PM
Cloudy Night
28°
Feels Like 19°
0
Humidity: 60%
UV Index: 0
Wind: 8 mph
9 PM
Cloudy Night
27°
Feels Like 18°
0
Humidity: 62%
UV Index: 0
Wind: 9 mph
10 PM
Cloudy Night
27°
Feels Like 16°
0
Humidity: 63%
UV Index: 0
Wind: 9 mph
11 PM
Cloudy Night
25°
Feels Like 16°
0
Frost Risk: 51%
Humidity: 65%
UV Index: 0
Wind: 9 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 8.41 µg/m³
  • PM10: 9.22 µg/m³
  • O3: 0.041 ppm
  • NO2: 4.9 ppb
  • SO2: 0.6 ppb
  • CO: 0.21 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: 4.2 µg/m³
  • PM10: 4.66 µg/m³
  • O3: 0.041 ppm
  • NO2: 3.8 ppb
  • SO2: 0.5 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.74 µg/m³
  • PM10: 3.17 µg/m³
  • O3: 0.040 ppm
  • NO2: 3.9 ppb
  • SO2: 0.5 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.72 µg/m³
  • PM10: 3.39 µg/m³
  • O3: 0.039 ppm
  • NO2: 4.9 ppb
  • SO2: 0.5 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.01 µg/m³
  • PM10: 3.97 µg/m³
  • O3: 0.038 ppm
  • NO2: 6.2 ppb
  • SO2: 0.6 ppb
  • CO: 0.21 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.05 µg/m³
  • PM10: 4.14 µg/m³
  • O3: 0.040 ppm
  • NO2: 5.5 ppb
  • SO2: 0.6 ppb
  • CO: 0.21 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.93 µg/m³
  • PM10: 3.96 µg/m³
  • O3: 0.042 ppm
  • NO2: 4.2 ppb
  • SO2: 0.5 ppb
  • CO: 0.20 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: 2.41 µg/m³
  • PM10: 3.17 µg/m³
  • O3: 0.045 ppm
  • NO2: 2.8 ppb
  • SO2: 0.5 ppb
  • CO: 0.18 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.59 µg/m³
  • PM10: 3.28 µg/m³
  • O3: 0.047 ppm
  • NO2: 2.4 ppb
  • SO2: 0.4 ppb
  • CO: 0.17 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: 2.95 µg/m³
  • PM10: 3.63 µg/m³
  • O3: 0.048 ppm
  • NO2: 2.3 ppb
  • SO2: 0.4 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.59 µg/m³
  • PM10: 4.35 µg/m³
  • O3: 0.049 ppm
  • NO2: 2.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.33 µg/m³
  • PM10: 5.28 µg/m³
  • O3: 0.048 ppm
  • NO2: 3.4 ppb
  • SO2: 0.5 ppb
  • CO: 0.18 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.7 µg/m³
  • PM10: 5.81 µg/m³
  • O3: 0.046 ppm
  • NO2: 4.8 ppb
  • SO2: 0.5 ppb
  • CO: 0.18 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.01 µg/m³
  • PM10: 6.36 µg/m³
  • O3: 0.043 ppm
  • NO2: 7.5 ppb
  • SO2: 0.5 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.38 µg/m³
  • PM10: 7.06 µg/m³
  • O3: 0.038 ppm
  • NO2: 10.7 ppb
  • SO2: 0.5 ppb
  • CO: 0.22 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.71 µg/m³
  • PM10: 7.7 µg/m³
  • O3: 0.035 ppm
  • NO2: 12.3 ppb
  • SO2: 0.6 ppb
  • CO: 0.23 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.79 µg/m³
  • PM10: 7.92 µg/m³
  • O3: 0.033 ppm
  • NO2: 12.3 ppb
  • SO2: 0.6 ppb
  • CO: 0.24 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.78 µg/m³
  • PM10: 7.95 µg/m³
  • O3: 0.032 ppm
  • NO2: 11.7 ppb
  • SO2: 0.6 ppb
  • CO: 0.24 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.71 µg/m³
  • PM10: 7.86 µg/m³
  • O3: 0.032 ppm
  • NO2: 10.8 ppb
  • SO2: 0.6 ppb
  • CO: 0.23 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.56 µg/m³
  • PM10: 7.63 µg/m³
  • O3: 0.031 ppm
  • NO2: 10.1 ppb
  • SO2: 0.5 ppb
  • CO: 0.23 ppm

Health Recommendations:

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