Hourly Weather | Today Tuesday, July 21, 2026
Watertown, South Dakota
4 AM
Night
64°
Feels Like 61°
0
Humidity: 84%
UV Index: 0
Wind: 12 mph
5 AM
Night
63°
Feels Like 59°
0
Humidity: 86%
UV Index: 0
Wind: 12 mph
6 AM
Night
63°
Feels Like 59°
0
Humidity: 88%
UV Index: 0
Wind: 12 mph
7 AM
Cloudy Weather
63°
Feels Like 61°
0
Humidity: 85%
UV Index: 1
Wind: 12 mph
8 AM
Cloudy Weather
64°
Feels Like 63°
0
Humidity: 81%
UV Index: 2
Wind: 14 mph
9 AM
Cloudy Weather
66°
Feels Like 64°
0
Humidity: 77%
UV Index: 3
Wind: 14 mph
10 AM
Cloudy Weather
66°
Feels Like 68°
0
Humidity: 70%
UV Index: 5
Wind: 15 mph
11 AM
Cloudy Weather
70°
Feels Like 72°
0
Humidity: 62%
UV Index: 7
Wind: 15 mph
12 PM
Cloudy Weather
72°
Feels Like 75°
0
Humidity: 56%
UV Index: 8
Wind: 15 mph
1 PM
Cloudy Weather
73°
Feels Like 77°
0
Humidity: 50%
UV Index: 9
Wind: 16 mph
2 PM
Cloudy Weather
75°
Feels Like 79°
0
Humidity: 47%
UV Index: 8
Wind: 15 mph
3 PM
Cloudy Weather
77°
Feels Like 79°
0
Humidity: 44%
UV Index: 7
Wind: 16 mph
4 PM
Cloudy Weather
75°
Feels Like 77°
0
Humidity: 45%
UV Index: 5
Wind: 15 mph
5 PM
Cloudy Weather
77°
Feels Like 77°
0
Humidity: 44%
UV Index: 3
Wind: 15 mph
6 PM
Cloudy Weather
75°
Feels Like 73°
0
Humidity: 45%
UV Index: 2
Wind: 14 mph
7 PM
Cloudy Weather
75°
Feels Like 72°
0
Humidity: 47%
UV Index: 1
Wind: 12 mph
8 PM
Cloudy Weather
72°
Feels Like 70°
0
Humidity: 51%
UV Index: 0
Wind: 11 mph
9 PM
Cloudy Weather
68°
Feels Like 66°
0
Humidity: 58%
UV Index: 0
Wind: 7 mph
10 PM
Cloudy Night
66°
Feels Like 63°
0
Humidity: 64%
UV Index: 0
Wind: 6 mph
11 PM
Cloudy Night
63°
Feels Like 63°
0
Humidity: 70%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

4 AM
34 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 3.32 µg/m³
  • PM10: 3.36 µg/m³
  • O3: 0.037 ppm
  • NO2: 0.6 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

5 AM
32 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.01 µg/m³
  • PM10: 2.04 µg/m³
  • O3: 0.035 ppm
  • NO2: 0.5 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.23 µg/m³
  • PM10: 1.25 µg/m³
  • O3: 0.032 ppm
  • NO2: 0.5 ppb
  • SO2: 0.1 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.79 µg/m³
  • PM10: 0.81 µg/m³
  • O3: 0.029 ppm
  • NO2: 0.5 ppb
  • SO2: 0.1 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.53 µg/m³
  • PM10: 0.54 µg/m³
  • O3: 0.026 ppm
  • NO2: 0.6 ppb
  • SO2: 0 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.5 µg/m³
  • PM10: 0.5 µg/m³
  • O3: 0.024 ppm
  • NO2: 0.5 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.5 µg/m³
  • PM10: 0.5 µg/m³
  • O3: 0.024 ppm
  • NO2: 0.4 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.5 µg/m³
  • PM10: 0.5 µg/m³
  • O3: 0.027 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.5 µg/m³
  • PM10: 0.5 µg/m³
  • O3: 0.029 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.56 µg/m³
  • PM10: 0.56 µg/m³
  • O3: 0.031 ppm
  • NO2: 0.1 ppb
  • SO2: 0 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.71 µg/m³
  • PM10: 0.72 µg/m³
  • O3: 0.033 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 0.9 µg/m³
  • PM10: 0.91 µg/m³
  • O3: 0.035 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.14 µg/m³
  • PM10: 1.15 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.41 µg/m³
  • PM10: 1.42 µg/m³
  • O3: 0.037 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.63 µg/m³
  • PM10: 1.64 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.3 ppb
  • SO2: 0 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.76 µg/m³
  • PM10: 1.77 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.3 ppb
  • SO2: 0 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.81 µg/m³
  • PM10: 1.83 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.4 ppb
  • SO2: 0 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.81 µg/m³
  • PM10: 1.83 µg/m³
  • O3: 0.037 ppm
  • NO2: 0.5 ppb
  • SO2: 0 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.77 µg/m³
  • PM10: 1.79 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.6 ppb
  • SO2: 0 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.78 µg/m³
  • PM10: 1.81 µg/m³
  • O3: 0.031 ppm
  • NO2: 1 ppb
  • SO2: 0 ppb
  • CO: 0.13 ppm

Health Recommendations:

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