Hourly Weather | Today Wednesday, March 18, 2026
Janesville, Wisconsin
4 AM
Snowy Weather
16°
Feels Like -8°
62
Frost Risk: 100%
Humidity: 100%
UV Index: 0
Wind: 18 mph
5 AM
Cloudy Weather
18°
Feels Like -2°
40
Frost Risk: 100%
Humidity: 100%
UV Index: 0
Wind: 18 mph
6 AM
Cloudy Weather
19°
Feels Like
34
Frost Risk: 100%
Humidity: 100%
UV Index: 0
Wind: 17 mph
7 AM
Cloudy Weather
21°
Feels Like
24
Frost Risk: 100%
Humidity: 100%
UV Index: 0
Wind: 16 mph
8 AM
Cloudy Weather
23°
Feels Like
4
Frost Risk: 99%
Humidity: 94%
UV Index: 0
Wind: 15 mph
9 AM
Cloudy Weather
25°
Feels Like 10°
4
Frost Risk: 99%
Humidity: 95%
UV Index: 1
Wind: 15 mph
10 AM
Cloudy Weather
28°
Feels Like 16°
4
Humidity: 92%
UV Index: 1
Wind: 15 mph
11 AM
Cloudy Weather
30°
Feels Like 18°
4
Humidity: 87%
UV Index: 2
Wind: 15 mph
12 PM
Cloudy Weather
30°
Feels Like 21°
4
Humidity: 83%
UV Index: 2
Wind: 15 mph
1 PM
Cloudy Weather
34°
Feels Like 23°
2
Humidity: 80%
UV Index: 2
Wind: 15 mph
2 PM
Cloudy Weather
36°
Feels Like 30°
0
Humidity: 74%
UV Index: 3
Wind: 10 mph
3 PM
Cloudy Weather
36°
Feels Like 30°
0
Humidity: 69%
UV Index: 3
Wind: 10 mph
4 PM
Cloudy Weather
37°
Feels Like 34°
0
Humidity: 61%
UV Index: 2
Wind: 10 mph
5 PM
Cloudy Weather
37°
Feels Like 32°
0
Humidity: 68%
UV Index: 1
Wind: 9 mph
6 PM
Cloudy Weather
36°
Feels Like 30°
0
Humidity: 74%
UV Index: 1
Wind: 8 mph
7 PM
Cloudy Weather
34°
Feels Like 30°
0
Humidity: 81%
UV Index: 0
Wind: 7 mph
8 PM
Rainy Weather
34°
Feels Like 28°
51
Humidity: 85%
UV Index: 0
Wind: 6 mph
9 PM
Cloudy Weather
30°
Feels Like 30°
47
Humidity: 91%
UV Index: 0
Wind: 5 mph
10 PM
Cloudy Weather
30°
Feels Like 30°
35
Humidity: 98%
UV Index: 0
Wind: 4 mph
11 PM
Cloudy Weather
28°
Feels Like 28°
19
Frost Risk: 80%
Humidity: 100%
UV Index: 0
Wind: 4 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 3.84 µg/m³
  • PM10: 3.95 µg/m³
  • O3: 0.052 ppm
  • NO2: 1.7 ppb
  • SO2: 0.9 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.35 µg/m³
  • PM10: 4.48 µg/m³
  • O3: 0.051 ppm
  • NO2: 1.7 ppb
  • SO2: 1 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.72 µg/m³
  • PM10: 4.9 µg/m³
  • O3: 0.050 ppm
  • NO2: 1.7 ppb
  • SO2: 1 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.92 µg/m³
  • PM10: 5.14 µg/m³
  • O3: 0.049 ppm
  • NO2: 1.6 ppb
  • SO2: 1.1 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.98 µg/m³
  • PM10: 5.27 µg/m³
  • O3: 0.049 ppm
  • NO2: 1.8 ppb
  • SO2: 1.1 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.94 µg/m³
  • PM10: 5.33 µg/m³
  • O3: 0.048 ppm
  • NO2: 2.3 ppb
  • SO2: 1.2 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.16 µg/m³
  • PM10: 5.65 µg/m³
  • O3: 0.048 ppm
  • NO2: 2 ppb
  • SO2: 1.2 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 6.22 µg/m³
  • PM10: 6.82 µg/m³
  • O3: 0.048 ppm
  • NO2: 1.7 ppb
  • SO2: 1.2 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: 8.43 µg/m³
  • PM10: 9.14 µg/m³
  • O3: 0.049 ppm
  • NO2: 1.5 ppb
  • SO2: 1 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

1 PM
49 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 11.75 µg/m³
  • PM10: 12.56 µg/m³
  • O3: 0.052 ppm
  • NO2: 1.4 ppb
  • SO2: 0.8 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

2 PM
58 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 15.88 µg/m³
  • PM10: 16.81 µg/m³
  • O3: 0.055 ppm
  • NO2: 1.4 ppb
  • SO2: 0.6 ppb
  • CO: 0.16 ppm

Health Recommendations:

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

3 PM
67 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 19.85 µg/m³
  • PM10: 20.91 µg/m³
  • O3: 0.056 ppm
  • NO2: 1.8 ppb
  • SO2: 0.5 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

4 PM
74 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 23.01 µg/m³
  • PM10: 24.19 µg/m³
  • O3: 0.057 ppm
  • NO2: 2.3 ppb
  • SO2: 0.4 ppb
  • CO: 0.18 ppm

Health Recommendations:

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

5 PM
78 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 25.29 µg/m³
  • PM10: 26.58 µg/m³
  • O3: 0.058 ppm
  • NO2: 3.3 ppb
  • SO2: 0.4 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

6 PM
81 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 26.29 µg/m³
  • PM10: 27.66 µg/m³
  • O3: 0.055 ppm
  • NO2: 5.2 ppb
  • SO2: 0.4 ppb
  • CO: 0.21 ppm

Health Recommendations:

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

7 PM
81 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 26.4 µg/m³
  • PM10: 27.82 µg/m³
  • O3: 0.050 ppm
  • NO2: 7.4 ppb
  • SO2: 0.3 ppb
  • CO: 0.22 ppm

Health Recommendations:

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

8 PM
80 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 26 µg/m³
  • PM10: 27.45 µg/m³
  • O3: 0.047 ppm
  • NO2: 7.6 ppb
  • SO2: 0.2 ppb
  • CO: 0.23 ppm

Health Recommendations:

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

9 PM
78 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 25.32 µg/m³
  • PM10: 26.73 µg/m³
  • O3: 0.046 ppm
  • NO2: 6.9 ppb
  • SO2: 0.2 ppb
  • CO: 0.23 ppm

Health Recommendations:

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

10 PM
76 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 24.27 µg/m³
  • PM10: 25.58 µg/m³
  • O3: 0.046 ppm
  • NO2: 5.8 ppb
  • SO2: 0.2 ppb
  • CO: 0.22 ppm

Health Recommendations:

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

11 PM
73 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 22.85 µg/m³
  • PM10: 24.09 µg/m³
  • O3: 0.046 ppm
  • NO2: 5.1 ppb
  • SO2: 0.2 ppb
  • CO: 0.21 ppm

Health Recommendations:

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