Hourly Weather | Today Wednesday, March 18, 2026
Frederick, Maryland
11 AM
Cloudy Weather
34°
Feels Like 41°
0
Humidity: 41%
UV Index: 3
Wind: 4 mph
12 PM
Cloudy Weather
36°
Feels Like 41°
0
Humidity: 36%
UV Index: 3
Wind: 6 mph
1 PM
Cloudy Weather
37°
Feels Like 39°
0
Humidity: 33%
UV Index: 3
Wind: 7 mph
2 PM
Cloudy Weather
39°
Feels Like 39°
1
Humidity: 31%
UV Index: 3
Wind: 8 mph
3 PM
Cloudy Weather
39°
Feels Like 39°
1
Humidity: 30%
UV Index: 3
Wind: 8 mph
4 PM
Cloudy Weather
43°
Feels Like 41°
1
Humidity: 29%
UV Index: 2
Wind: 8 mph
5 PM
Cloudy Weather
41°
Feels Like 37°
1
Humidity: 32%
UV Index: 2
Wind: 8 mph
6 PM
Cloudy Weather
39°
Feels Like 37°
1
Humidity: 34%
UV Index: 1
Wind: 7 mph
7 PM
Cloudy Weather
37°
Feels Like 34°
1
Humidity: 37%
UV Index: 0
Wind: 6 mph
8 PM
Cloudy Weather
36°
Feels Like 34°
0
Humidity: 44%
UV Index: 0
Wind: 5 mph
9 PM
Cloudy Weather
32°
Feels Like 30°
0
Humidity: 52%
UV Index: 0
Wind: 6 mph
10 PM
Cloudy Weather
28°
Feels Like 27°
0
Humidity: 62%
UV Index: 0
Wind: 6 mph
11 PM
Cloudy Weather
30°
Feels Like 27°
0
Humidity: 61%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 1.5 µg/m³
  • PM10: 2.38 µg/m³
  • O3: 0.048 ppm
  • NO2: 1.9 ppb
  • SO2: 0.9 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.69 µg/m³
  • PM10: 2.41 µg/m³
  • O3: 0.050 ppm
  • NO2: 1.5 ppb
  • SO2: 0.7 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.9 µg/m³
  • PM10: 2.5 µg/m³
  • O3: 0.052 ppm
  • NO2: 1.2 ppb
  • SO2: 0.6 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.24 µg/m³
  • PM10: 2.79 µg/m³
  • O3: 0.053 ppm
  • NO2: 0.9 ppb
  • SO2: 0.5 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.59 µg/m³
  • PM10: 3.12 µg/m³
  • O3: 0.056 ppm
  • NO2: 0.8 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 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: 2.8 µg/m³
  • PM10: 3.32 µg/m³
  • O3: 0.057 ppm
  • NO2: 0.7 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.97 µg/m³
  • PM10: 3.51 µg/m³
  • O3: 0.058 ppm
  • NO2: 0.7 ppb
  • SO2: 0.4 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.24 µg/m³
  • PM10: 3.95 µg/m³
  • O3: 0.057 ppm
  • NO2: 1.1 ppb
  • SO2: 0.3 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.4 µg/m³
  • PM10: 4.42 µg/m³
  • O3: 0.053 ppm
  • NO2: 1.9 ppb
  • SO2: 0.3 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.51 µg/m³
  • PM10: 4.79 µg/m³
  • O3: 0.050 ppm
  • NO2: 2.6 ppb
  • SO2: 0.3 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.69 µg/m³
  • PM10: 5.18 µg/m³
  • O3: 0.047 ppm
  • NO2: 3.1 ppb
  • SO2: 0.2 ppb
  • CO: 0.16 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.03 µg/m³
  • PM10: 5.74 µg/m³
  • O3: 0.045 ppm
  • NO2: 3.3 ppb
  • SO2: 0.2 ppb
  • CO: 0.16 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.43 µg/m³
  • PM10: 6.38 µg/m³
  • O3: 0.043 ppm
  • NO2: 3.4 ppb
  • SO2: 0.2 ppb
  • CO: 0.17 ppm

Health Recommendations:

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