Hourly Weather | Today Wednesday, March 18, 2026
Decatur, Illinois
5 AM
Cloudy Weather
25°
Feels Like
39
Frost Risk: 84%
Humidity: 88%
UV Index: 0
Wind: 18 mph
6 AM
Snowy Weather
27°
Feels Like
46
Humidity: 81%
UV Index: 0
Wind: 17 mph
7 AM
Cloudy Weather
28°
Feels Like 12°
42
Humidity: 79%
UV Index: 0
Wind: 16 mph
8 AM
Cloudy Weather
30°
Feels Like 12°
36
Humidity: 74%
UV Index: 0
Wind: 18 mph
9 AM
Snowy Weather
32°
Feels Like 16°
40
Humidity: 71%
UV Index: 1
Wind: 18 mph
10 AM
Cloudy Weather
36°
Feels Like 25°
36
Humidity: 67%
UV Index: 3
Wind: 18 mph
11 AM
Cloudy Weather
39°
Feels Like 32°
34
Humidity: 62%
UV Index: 4
Wind: 18 mph
12 PM
Cloudy Weather
45°
Feels Like 39°
34
Humidity: 57%
UV Index: 5
Wind: 17 mph
1 PM
Cloudy Weather
48°
Feels Like 45°
22
Humidity: 54%
UV Index: 5
Wind: 17 mph
2 PM
Cloudy Weather
52°
Feels Like 52°
0
Humidity: 51%
UV Index: 5
Wind: 12 mph
3 PM
Cloudy Weather
54°
Feels Like 54°
0
Humidity: 50%
UV Index: 4
Wind: 12 mph
4 PM
Cloudy Weather
55°
Feels Like 54°
0
Humidity: 49%
UV Index: 3
Wind: 10 mph
5 PM
Cloudy Weather
54°
Feels Like 52°
0
Humidity: 54%
UV Index: 2
Wind: 9 mph
6 PM
Cloudy Weather
52°
Feels Like 50°
0
Humidity: 59%
UV Index: 1
Wind: 7 mph
7 PM
Cloudy Weather
48°
Feels Like 46°
0
Humidity: 66%
UV Index: 0
Wind: 6 mph
8 PM
Cloudy Night
46°
Feels Like 45°
0
Humidity: 72%
UV Index: 0
Wind: 6 mph
9 PM
Cloudy Night
45°
Feels Like 43°
0
Humidity: 79%
UV Index: 0
Wind: 6 mph
10 PM
Cloudy Night
43°
Feels Like 39°
0
Humidity: 83%
UV Index: 0
Wind: 6 mph
11 PM
Cloudy Night
43°
Feels Like 39°
0
Humidity: 83%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 3.83 µg/m³
  • PM10: 4.47 µg/m³
  • O3: 0.051 ppm
  • NO2: 1.5 ppb
  • SO2: 1.1 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.1 µg/m³
  • PM10: 4.82 µg/m³
  • O3: 0.050 ppm
  • NO2: 1.5 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
46 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 4.33 µg/m³
  • PM10: 5.13 µg/m³
  • O3: 0.049 ppm
  • NO2: 1.6 ppb
  • SO2: 0.9 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: 4.61 µg/m³
  • PM10: 5.49 µg/m³
  • O3: 0.049 ppm
  • NO2: 2 ppb
  • SO2: 0.9 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.68 µg/m³
  • PM10: 5.64 µg/m³
  • O3: 0.048 ppm
  • NO2: 2.7 ppb
  • SO2: 0.9 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.55 µg/m³
  • PM10: 5.56 µg/m³
  • O3: 0.047 ppm
  • NO2: 2.8 ppb
  • SO2: 1 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 4.34 µg/m³
  • PM10: 5.38 µg/m³
  • O3: 0.047 ppm
  • NO2: 2.6 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
44 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 4.37 µg/m³
  • PM10: 5.42 µg/m³
  • O3: 0.047 ppm
  • NO2: 2.2 ppb
  • SO2: 1.4 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 5.07 µg/m³
  • PM10: 6.19 µg/m³
  • O3: 0.049 ppm
  • NO2: 1.9 ppb
  • SO2: 1.5 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 6.77 µg/m³
  • PM10: 8.03 µg/m³
  • O3: 0.054 ppm
  • NO2: 1.5 ppb
  • SO2: 1.7 ppb
  • CO: 0.14 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 8.02 µg/m³
  • PM10: 9.43 µg/m³
  • O3: 0.057 ppm
  • NO2: 1.3 ppb
  • SO2: 1.8 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
67 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 8.51 µg/m³
  • PM10: 10.04 µg/m³
  • O3: 0.059 ppm
  • NO2: 1.3 ppb
  • SO2: 1.9 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
51 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 7.69 µg/m³
  • PM10: 9.37 µg/m³
  • O3: 0.054 ppm
  • NO2: 2.2 ppb
  • SO2: 1.5 ppb
  • CO: 0.15 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 7.54 µg/m³
  • PM10: 9.44 µg/m³
  • O3: 0.045 ppm
  • NO2: 4.6 ppb
  • SO2: 1 ppb
  • CO: 0.18 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: 7.93 µg/m³
  • PM10: 10.13 µg/m³
  • O3: 0.039 ppm
  • NO2: 7.9 ppb
  • SO2: 0.8 ppb
  • CO: 0.20 ppm

Health Recommendations:

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

8 PM
38 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 9.03 µg/m³
  • PM10: 11.51 µg/m³
  • O3: 0.035 ppm
  • NO2: 9.9 ppb
  • SO2: 0.8 ppb
  • CO: 0.22 ppm

Health Recommendations:

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

9 PM
44 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 10.52 µg/m³
  • PM10: 13.23 µg/m³
  • O3: 0.033 ppm
  • NO2: 10.5 ppb
  • SO2: 0.8 ppb
  • CO: 0.23 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 11.87 µg/m³
  • PM10: 14.71 µg/m³
  • O3: 0.032 ppm
  • NO2: 10.6 ppb
  • SO2: 0.7 ppb
  • CO: 0.24 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 12.55 µg/m³
  • PM10: 15.39 µg/m³
  • O3: 0.031 ppm
  • NO2: 9.8 ppb
  • SO2: 0.6 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.