Hourly Weather | Today Wednesday, March 18, 2026
Gaithersburg, Maryland
6 AM
Cloudy Night
27°
Feels Like 25°
0
Humidity: 60%
UV Index: 0
Wind: 5 mph
7 AM
Cloudy Night
27°
Feels Like 25°
0
Humidity: 61%
UV Index: 0
Wind: 5 mph
8 AM
Cloudy Weather
28°
Feels Like 27°
0
Humidity: 54%
UV Index: 1
Wind: 6 mph
9 AM
Cloudy Weather
30°
Feels Like 32°
0
Humidity: 50%
UV Index: 1
Wind: 5 mph
10 AM
Cloudy Weather
32°
Feels Like 39°
0
Humidity: 45%
UV Index: 2
Wind: 4 mph
11 AM
Cloudy Weather
34°
Feels Like 45°
0
Humidity: 40%
UV Index: 4
Wind: 4 mph
12 PM
Cloudy Weather
36°
Feels Like 45°
0
Humidity: 37%
UV Index: 4
Wind: 5 mph
1 PM
Cloudy Weather
37°
Feels Like 43°
0
Humidity: 34%
UV Index: 4
Wind: 7 mph
2 PM
Cloudy Weather
39°
Feels Like 43°
1
Humidity: 33%
UV Index: 4
Wind: 7 mph
3 PM
Cloudy Weather
39°
Feels Like 43°
1
Humidity: 31%
UV Index: 3
Wind: 7 mph
4 PM
Cloudy Weather
41°
Feels Like 43°
1
Humidity: 29%
UV Index: 2
Wind: 7 mph
5 PM
Cloudy Weather
39°
Feels Like 41°
1
Humidity: 31%
UV Index: 2
Wind: 6 mph
6 PM
Cloudy Weather
39°
Feels Like 39°
1
Humidity: 33%
UV Index: 1
Wind: 6 mph
7 PM
Cloudy Weather
37°
Feels Like 36°
1
Humidity: 38%
UV Index: 0
Wind: 6 mph
8 PM
Cloudy Weather
36°
Feels Like 34°
0
Humidity: 45%
UV Index: 0
Wind: 5 mph
9 PM
Cloudy Weather
34°
Feels Like 30°
0
Humidity: 53%
UV Index: 0
Wind: 6 mph
10 PM
Cloudy Weather
32°
Feels Like 28°
0
Humidity: 58%
UV Index: 0
Wind: 6 mph
11 PM
Cloudy Weather
34°
Feels Like 28°
0
Humidity: 56%
UV Index: 0
Wind: 7 mph

Hourly Air Quality Forecast - AQI (US EPA)

6 AM
43 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.03 µg/m³
  • PM10: 2.28 µg/m³
  • O3: 0.046 ppm
  • NO2: 1.1 ppb
  • SO2: 0.5 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.1 µg/m³
  • PM10: 2.4 µg/m³
  • O3: 0.045 ppm
  • NO2: 1.2 ppb
  • SO2: 0.5 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

8 AM
41 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.19 µg/m³
  • PM10: 2.53 µg/m³
  • O3: 0.044 ppm
  • NO2: 1.5 ppb
  • SO2: 0.5 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.24 µg/m³
  • PM10: 2.53 µg/m³
  • O3: 0.044 ppm
  • NO2: 2.3 ppb
  • SO2: 0.5 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.29 µg/m³
  • PM10: 2.47 µg/m³
  • O3: 0.044 ppm
  • NO2: 2.5 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 AM
41 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.44 µg/m³
  • PM10: 2.51 µg/m³
  • O3: 0.044 ppm
  • NO2: 2.3 ppb
  • SO2: 0.6 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.42 µg/m³
  • PM10: 2.1 µg/m³
  • O3: 0.048 ppm
  • NO2: 1.7 ppb
  • SO2: 0.7 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.54 µg/m³
  • PM10: 2.11 µg/m³
  • O3: 0.050 ppm
  • NO2: 1.4 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
48 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 1.8 µg/m³
  • PM10: 2.37 µg/m³
  • O3: 0.051 ppm
  • NO2: 1.3 ppb
  • SO2: 0.6 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.01 µg/m³
  • PM10: 2.59 µg/m³
  • O3: 0.053 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.

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

Pollutant Concentrations:

  • PM2.5: 2.04 µg/m³
  • PM10: 2.6 µg/m³
  • O3: 0.055 ppm
  • NO2: 1.1 ppb
  • SO2: 0.5 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.

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

Pollutant Concentrations:

  • PM2.5: 1.92 µg/m³
  • PM10: 2.47 µg/m³
  • O3: 0.055 ppm
  • NO2: 1.1 ppb
  • SO2: 0.5 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.

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

Pollutant Concentrations:

  • PM2.5: 1.93 µg/m³
  • PM10: 2.62 µg/m³
  • O3: 0.053 ppm
  • NO2: 1.8 ppb
  • SO2: 0.4 ppb
  • CO: 0.14 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: 2.15 µg/m³
  • PM10: 3.11 µg/m³
  • O3: 0.048 ppm
  • NO2: 3.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.16 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.35 µg/m³
  • PM10: 3.59 µg/m³
  • O3: 0.044 ppm
  • NO2: 4.2 ppb
  • SO2: 0.3 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.66 µg/m³
  • PM10: 4.13 µg/m³
  • O3: 0.042 ppm
  • NO2: 4.3 ppb
  • SO2: 0.2 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.93 µg/m³
  • PM10: 4.58 µg/m³
  • O3: 0.041 ppm
  • NO2: 4.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.28 µg/m³
  • PM10: 5.15 µg/m³
  • O3: 0.039 ppm
  • NO2: 4.3 ppb
  • SO2: 0.2 ppb
  • CO: 0.18 ppm

Health Recommendations:

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