Hourly Weather | Today Monday, September 21, 2026
Norwalk, Connecticut
3 PM
Cloudy Weather
66°
Feels Like 68°
7
Humidity: 62%
UV Index: 3
Wind: 10 mph
4 PM
Cloudy Weather
68°
Feels Like 66°
7
Humidity: 62%
UV Index: 1
Wind: 9 mph
5 PM
Cloudy Weather
66°
Feels Like 66°
7
Humidity: 63%
UV Index: 2
Wind: 9 mph
6 PM
Cloudy Weather
66°
Feels Like 64°
7
Humidity: 65%
UV Index: 1
Wind: 8 mph
7 PM
Cloudy Night
66°
Feels Like 63°
5
Humidity: 71%
UV Index: 0
Wind: 8 mph
8 PM
Cloudy Weather
64°
Feels Like 63°
0
Humidity: 73%
UV Index: 0
Wind: 7 mph
9 PM
Cloudy Weather
63°
Feels Like 61°
0
Humidity: 76%
UV Index: 0
Wind: 7 mph
10 PM
Cloudy Weather
63°
Feels Like 61°
0
Humidity: 75%
UV Index: 0
Wind: 8 mph
11 PM
Cloudy Weather
61°
Feels Like 59°
0
Humidity: 76%
UV Index: 0
Wind: 8 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 4.99 µg/m³
  • PM10: 7.51 µg/m³
  • O3: 0.039 ppm
  • NO2: 4.3 ppb
  • SO2: 1.1 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.18 µg/m³
  • PM10: 7.71 µg/m³
  • O3: 0.041 ppm
  • NO2: 4.2 ppb
  • SO2: 1 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.94 µg/m³
  • PM10: 7.54 µg/m³
  • O3: 0.042 ppm
  • NO2: 4.4 ppb
  • SO2: 0.9 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.63 µg/m³
  • PM10: 7.39 µg/m³
  • O3: 0.041 ppm
  • NO2: 4.8 ppb
  • SO2: 0.8 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.43 µg/m³
  • PM10: 7.37 µg/m³
  • O3: 0.040 ppm
  • NO2: 5.4 ppb
  • SO2: 0.8 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.36 µg/m³
  • PM10: 7.47 µg/m³
  • O3: 0.040 ppm
  • NO2: 5.5 ppb
  • SO2: 0.8 ppb
  • CO: 0.19 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: 4.33 µg/m³
  • PM10: 7.67 µg/m³
  • O3: 0.040 ppm
  • NO2: 5.3 ppb
  • SO2: 0.8 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.35 µg/m³
  • PM10: 8.04 µg/m³
  • O3: 0.040 ppm
  • NO2: 5 ppb
  • SO2: 0.8 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.25 µg/m³
  • PM10: 8.17 µg/m³
  • O3: 0.040 ppm
  • NO2: 4.7 ppb
  • SO2: 0.8 ppb
  • CO: 0.19 ppm

Health Recommendations:

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