Hourly Weather | Today Monday, September 21, 2026
Watertown, South Dakota
2 PM
Rainy Weather
55°
Feels Like 52°
40
Humidity: 76%
UV Index: 1
Wind: 8 mph
3 PM
Cloudy Weather
57°
Feels Like 55°
37
Humidity: 73%
UV Index: 2
Wind: 8 mph
4 PM
Cloudy Weather
57°
Feels Like 55°
33
Humidity: 71%
UV Index: 1
Wind: 9 mph
5 PM
Cloudy Weather
55°
Feels Like 54°
32
Humidity: 72%
UV Index: 1
Wind: 8 mph
6 PM
Cloudy Weather
55°
Feels Like 52°
32
Humidity: 75%
UV Index: 0
Wind: 8 mph
7 PM
Cloudy Weather
54°
Feels Like 50°
25
Humidity: 80%
UV Index: 0
Wind: 8 mph
8 PM
Cloudy Night
52°
Feels Like 48°
12
Humidity: 85%
UV Index: 0
Wind: 7 mph
9 PM
Cloudy Night
50°
Feels Like 46°
12
Humidity: 89%
UV Index: 0
Wind: 7 mph
10 PM
Cloudy Weather
50°
Feels Like 46°
12
Humidity: 90%
UV Index: 0
Wind: 7 mph
11 PM
Cloudy Weather
48°
Feels Like 46°
12
Humidity: 92%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 0.87 µg/m³
  • PM10: 0.93 µg/m³
  • O3: 0.021 ppm
  • NO2: 1.1 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.85 µg/m³
  • PM10: 0.92 µg/m³
  • O3: 0.023 ppm
  • NO2: 1 ppb
  • SO2: 0 ppb
  • CO: 0.14 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: 0.8 µg/m³
  • PM10: 0.86 µg/m³
  • O3: 0.025 ppm
  • NO2: 0.9 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.76 µg/m³
  • PM10: 0.81 µg/m³
  • O3: 0.027 ppm
  • NO2: 0.9 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.73 µg/m³
  • PM10: 0.78 µg/m³
  • O3: 0.028 ppm
  • NO2: 1 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.72 µg/m³
  • PM10: 0.76 µg/m³
  • O3: 0.027 ppm
  • NO2: 1.1 ppb
  • SO2: 0 ppb
  • CO: 0.14 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: 0.71 µg/m³
  • PM10: 0.76 µg/m³
  • O3: 0.027 ppm
  • NO2: 1.2 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.73 µg/m³
  • PM10: 0.78 µg/m³
  • O3: 0.026 ppm
  • NO2: 1.3 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.76 µg/m³
  • PM10: 0.82 µg/m³
  • O3: 0.025 ppm
  • NO2: 1.4 ppb
  • SO2: 0 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.79 µg/m³
  • PM10: 0.86 µg/m³
  • O3: 0.023 ppm
  • NO2: 1.5 ppb
  • SO2: 0 ppb
  • CO: 0.15 ppm

Health Recommendations:

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