Hourly Weather | Today Monday, September 21, 2026
Frederick, Maryland
3 PM
Rainy Weather
66°
Feels Like 64°
45
Humidity: 81%
UV Index: 1
Wind: 7 mph
4 PM
Cloudy Weather
64°
Feels Like 64°
45
Humidity: 91%
UV Index: 1
Wind: 7 mph
5 PM
Cloudy Weather
64°
Feels Like 64°
34
Humidity: 97%
UV Index: 0
Wind: 7 mph
6 PM
Cloudy Weather
63°
Feels Like 63°
34
Humidity: 98%
UV Index: 0
Wind: 7 mph
7 PM
Cloudy Weather
63°
Feels Like 61°
37
Humidity: 100%
UV Index: 0
Wind: 7 mph
8 PM
Cloudy Weather
64°
Feels Like 64°
44
Humidity: 94%
UV Index: 0
Wind: 6 mph
9 PM
Cloudy Weather
63°
Feels Like 63°
48
Humidity: 98%
UV Index: 0
Wind: 6 mph
10 PM
Rainy Weather
63°
Feels Like 59°
52
Humidity: 98%
UV Index: 0
Wind: 6 mph
11 PM
Rainy Weather
63°
Feels Like 57°
60
Humidity: 100%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 3.71 µg/m³
  • PM10: 4.47 µg/m³
  • O3: 0.024 ppm
  • NO2: 3.1 ppb
  • SO2: 0.5 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.13 µg/m³
  • PM10: 4.91 µg/m³
  • O3: 0.025 ppm
  • NO2: 3.3 ppb
  • SO2: 0.5 ppb
  • CO: 0.19 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.6 µg/m³
  • PM10: 5.42 µg/m³
  • O3: 0.025 ppm
  • NO2: 3.6 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
24 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 5 µg/m³
  • PM10: 5.76 µg/m³
  • O3: 0.026 ppm
  • NO2: 3.9 ppb
  • SO2: 0.5 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.24 µg/m³
  • PM10: 5.92 µg/m³
  • O3: 0.026 ppm
  • NO2: 3.9 ppb
  • SO2: 0.6 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.33 µg/m³
  • PM10: 5.95 µg/m³
  • O3: 0.027 ppm
  • NO2: 3.8 ppb
  • SO2: 0.6 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.3 µg/m³
  • PM10: 5.9 µg/m³
  • O3: 0.026 ppm
  • NO2: 3.6 ppb
  • SO2: 0.6 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.37 µg/m³
  • PM10: 5.96 µg/m³
  • O3: 0.026 ppm
  • NO2: 3.6 ppb
  • SO2: 0.7 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

11 PM
23 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 5.5 µg/m³
  • PM10: 6.07 µg/m³
  • O3: 0.024 ppm
  • NO2: 3.7 ppb
  • SO2: 0.6 ppb
  • CO: 0.20 ppm

Health Recommendations:

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