Hourly Weather | Today Friday, May 22, 2026
Portland, Maine
9 AM
Sunny Weather
46°
Feels Like 46°
0
Humidity: 60%
UV Index: 3
Wind: 8 mph
10 AM
Sunny Weather
52°
Feels Like 55°
0
Humidity: 48%
UV Index: 5
Wind: 8 mph
11 AM
Cloudy Weather
55°
Feels Like 63°
0
Humidity: 41%
UV Index: 7
Wind: 7 mph
12 PM
Cloudy Weather
61°
Feels Like 68°
0
Humidity: 35%
UV Index: 8
Wind: 8 mph
1 PM
Cloudy Weather
61°
Feels Like 70°
0
Humidity: 36%
UV Index: 9
Wind: 8 mph
2 PM
Cloudy Weather
63°
Feels Like 70°
0
Humidity: 35%
UV Index: 8
Wind: 9 mph
3 PM
Sunny Weather
63°
Feels Like 66°
0
Humidity: 38%
UV Index: 7
Wind: 10 mph
4 PM
Sunny Weather
61°
Feels Like 63°
0
Humidity: 39%
UV Index: 5
Wind: 13 mph
5 PM
Cloudy Weather
61°
Feels Like 59°
0
Humidity: 42%
UV Index: 3
Wind: 14 mph
6 PM
Cloudy Weather
59°
Feels Like 55°
0
Humidity: 45%
UV Index: 2
Wind: 14 mph
7 PM
Cloudy Weather
57°
Feels Like 54°
0
Humidity: 49%
UV Index: 1
Wind: 13 mph
8 PM
Cloudy Weather
55°
Feels Like 52°
0
Humidity: 55%
UV Index: 0
Wind: 10 mph
9 PM
Cloudy Night
54°
Feels Like 50°
0
Humidity: 60%
UV Index: 0
Wind: 9 mph
10 PM
Cloudy Night
52°
Feels Like 48°
0
Humidity: 66%
UV Index: 0
Wind: 7 mph
11 PM
Cloudy Night
52°
Feels Like 48°
0
Humidity: 68%
UV Index: 0
Wind: 7 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 0.61 µg/m³
  • PM10: 0.84 µg/m³
  • O3: 0.043 ppm
  • NO2: 1.6 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.58 µg/m³
  • PM10: 0.78 µg/m³
  • O3: 0.046 ppm
  • NO2: 1.2 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.66 µg/m³
  • PM10: 0.96 µg/m³
  • O3: 0.048 ppm
  • NO2: 1 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.98 µg/m³
  • PM10: 1.29 µg/m³
  • O3: 0.051 ppm
  • NO2: 0.9 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.29 µg/m³
  • PM10: 1.61 µg/m³
  • O3: 0.054 ppm
  • NO2: 0.8 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

2 PM
55 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.51 µg/m³
  • PM10: 1.84 µg/m³
  • O3: 0.056 ppm
  • NO2: 0.8 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

3 PM
59 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.78 µg/m³
  • PM10: 2.13 µg/m³
  • O3: 0.057 ppm
  • NO2: 0.9 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

4 PM
60 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.11 µg/m³
  • PM10: 2.49 µg/m³
  • O3: 0.057 ppm
  • NO2: 1.1 ppb
  • SO2: 0.4 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

5 PM
58 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.28 µg/m³
  • PM10: 2.68 µg/m³
  • O3: 0.057 ppm
  • NO2: 1.5 ppb
  • SO2: 0.5 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.39 µg/m³
  • PM10: 2.88 µg/m³
  • O3: 0.053 ppm
  • NO2: 2.6 ppb
  • SO2: 0.5 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.45 µg/m³
  • PM10: 3.12 µg/m³
  • O3: 0.048 ppm
  • NO2: 4.2 ppb
  • SO2: 0.6 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.41 µg/m³
  • PM10: 3.27 µg/m³
  • O3: 0.044 ppm
  • NO2: 5.6 ppb
  • SO2: 0.7 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.27 µg/m³
  • PM10: 3.28 µg/m³
  • O3: 0.039 ppm
  • NO2: 6 ppb
  • SO2: 0.7 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.24 µg/m³
  • PM10: 3.45 µg/m³
  • O3: 0.036 ppm
  • NO2: 6.5 ppb
  • SO2: 0.6 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.29 µg/m³
  • PM10: 3.66 µg/m³
  • O3: 0.033 ppm
  • NO2: 7.1 ppb
  • SO2: 0.6 ppb
  • CO: 0.15 ppm

Health Recommendations:

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