Hourly Weather | Today Saturday, August 29, 2026
Waltham, Massachusetts
3 PM
Cloudy Weather
79°
Feels Like 84°
0
Humidity: 36%
UV Index: 5
Wind: 6 mph
4 PM
Cloudy Weather
81°
Feels Like 82°
0
Humidity: 35%
UV Index: 4
Wind: 6 mph
5 PM
Cloudy Weather
79°
Feels Like 81°
0
Humidity: 35%
UV Index: 2
Wind: 6 mph
6 PM
Cloudy Weather
75°
Feels Like 75°
0
Humidity: 39%
UV Index: 1
Wind: 6 mph
7 PM
Cloudy Weather
73°
Feels Like 73°
0
Humidity: 45%
UV Index: 1
Wind: 7 mph
8 PM
Night
72°
Feels Like 70°
0
Humidity: 53%
UV Index: 0
Wind: 6 mph
9 PM
Night
70°
Feels Like 66°
0
Humidity: 60%
UV Index: 0
Wind: 6 mph
10 PM
Night
66°
Feels Like 64°
0
Humidity: 67%
UV Index: 0
Wind: 6 mph
11 PM
Night
63°
Feels Like 63°
0
Humidity: 74%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 2.26 µg/m³
  • PM10: 2.77 µg/m³
  • O3: 0.048 ppm
  • NO2: 0.4 ppb
  • SO2: 0.2 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.47 µg/m³
  • PM10: 2.97 µg/m³
  • O3: 0.050 ppm
  • NO2: 0.5 ppb
  • SO2: 0.2 ppb
  • CO: 0.11 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: 2.65 µg/m³
  • PM10: 3.16 µg/m³
  • O3: 0.051 ppm
  • NO2: 0.6 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.85 µg/m³
  • PM10: 3.41 µg/m³
  • O3: 0.048 ppm
  • NO2: 1.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.02 µg/m³
  • PM10: 3.62 µg/m³
  • O3: 0.041 ppm
  • NO2: 2.8 ppb
  • SO2: 0.2 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.06 µg/m³
  • PM10: 3.69 µg/m³
  • O3: 0.036 ppm
  • NO2: 3.7 ppb
  • SO2: 0.2 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.98 µg/m³
  • PM10: 3.54 µg/m³
  • O3: 0.034 ppm
  • NO2: 3.5 ppb
  • SO2: 0.2 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.14 µg/m³
  • PM10: 3.84 µg/m³
  • O3: 0.033 ppm
  • NO2: 3.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.13 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: 3.39 µg/m³
  • PM10: 4.31 µg/m³
  • O3: 0.033 ppm
  • NO2: 2.9 ppb
  • SO2: 0.2 ppb
  • CO: 0.13 ppm

Health Recommendations:

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