Hourly Weather | Today Monday, April 27, 2026
Active Weather Warnings
Decatur, Illinois
1 PM
Cloudy Weather
66°
Feels Like 63°
75
Humidity: 87%
UV Index: 2
Wind: 29 mph
2 PM
Cloudy Weather
66°
Feels Like 64°
40
Humidity: 84%
UV Index: 2
Wind: 28 mph
3 PM
Cloudy Weather
70°
Feels Like 64°
34
Humidity: 81%
UV Index: 2
Wind: 27 mph
4 PM
Cloudy Weather
70°
Feels Like 66°
39
Humidity: 78%
UV Index: 1
Wind: 24 mph
5 PM
Cloudy Weather
72°
Feels Like 68°
49
Humidity: 75%
UV Index: 1
Wind: 23 mph
6 PM
Stormy Weather
72°
Feels Like 63°
70
Humidity: 78%
UV Index: 0
Wind: 22 mph
7 PM
Stormy Weather
72°
Feels Like 63°
70
Humidity: 81%
UV Index: 0
Wind: 21 mph
8 PM
Stormy Weather
70°
Feels Like 63°
56
Humidity: 87%
UV Index: 0
Wind: 18 mph
9 PM
Cloudy Night
70°
Feels Like 66°
49
Humidity: 85%
UV Index: 0
Wind: 18 mph
10 PM
Cloudy Night
70°
Feels Like 66°
44
Humidity: 78%
UV Index: 0
Wind: 17 mph
11 PM
Cloudy Night
70°
Feels Like 66°
34
Humidity: 80%
UV Index: 0
Wind: 15 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 2.29 µg/m³
  • PM10: 2.64 µg/m³
  • O3: 0.030 ppm
  • NO2: 0.9 ppb
  • SO2: 0.5 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.95 µg/m³
  • PM10: 3.31 µg/m³
  • O3: 0.031 ppm
  • NO2: 1 ppb
  • SO2: 0.5 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 3.05 µg/m³
  • PM10: 3.33 µg/m³
  • O3: 0.031 ppm
  • NO2: 1 ppb
  • SO2: 0.5 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.87 µg/m³
  • PM10: 3.1 µg/m³
  • O3: 0.031 ppm
  • NO2: 0.9 ppb
  • SO2: 0.5 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.69 µg/m³
  • PM10: 2.87 µg/m³
  • O3: 0.031 ppm
  • NO2: 1.1 ppb
  • SO2: 0.4 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.47 µg/m³
  • PM10: 2.62 µg/m³
  • O3: 0.030 ppm
  • NO2: 1.5 ppb
  • SO2: 0.4 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.39 µg/m³
  • PM10: 2.55 µg/m³
  • O3: 0.028 ppm
  • NO2: 1.9 ppb
  • SO2: 0.4 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.34 µg/m³
  • PM10: 2.53 µg/m³
  • O3: 0.026 ppm
  • NO2: 2.2 ppb
  • SO2: 0.4 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2.2 µg/m³
  • PM10: 2.42 µg/m³
  • O3: 0.024 ppm
  • NO2: 2.4 ppb
  • SO2: 0.5 ppb
  • CO: 0.12 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 2 µg/m³
  • PM10: 2.24 µg/m³
  • O3: 0.023 ppm
  • NO2: 2.5 ppb
  • SO2: 0.5 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 1.83 µg/m³
  • PM10: 2.08 µg/m³
  • O3: 0.022 ppm
  • NO2: 2.6 ppb
  • SO2: 0.5 ppb
  • CO: 0.13 ppm

Health Recommendations:

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

Weather Alerts and Warnings for Decatur

Severe Future Possible

Severe Thunderstorm Watch

Severe Thunderstorm Watch issued April 27 at 11:49AM CDT until April 27 at 4:00PM CDT by NWS Lincoln IL
Apr 27, 11:49 AM Apr 27, 4:00 PM
SEVERE THUNDERSTORM WATCH 158 REMAINS VALID UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING AREAS

IN ILLINOIS THIS WATCH INCLUDES 22 COUNTIES

IN CENTRAL ILLINOIS

CHRISTIAN DE WITT LOGAN
MACON MCLEAN SANGAMON
SHELBY

IN EAST CENTRAL ILLINOIS

CHAMPAIGN CLARK COLES
CUMBERLAND DOUGLAS EDGAR
MOULTRIE PIATT VERMILION

IN SOUTHEAST ILLINOIS

CLAY CRAWFORD EFFINGHAM
JASPER LAWRENCE RICHLAND

THIS INCLUDES THE CITIES OF BLOOMINGTON, CHAMPAIGN, CHARLESTON,
CLINTON, DANVILLE, DECATUR, EFFINGHAM, FLORA, GREENUP,
LAWRENCEVILLE, LINCOLN, MARSHALL, MATTOON, MONTICELLO, NEWTON,
NORMAL, OLNEY, PARIS, ROBINSON, SHELBYVILLE, SPRINGFIELD,
SULLIVAN, TAYLORVILLE, TUSCOLA, AND URBANA.
Updated: Apr 27, 11:59 AM Source: NWS Alert
Severe Future Possible

Flood Watch

Flood Watch issued April 27 at 11:42AM CDT until April 27 at 10:00PM CDT by NWS Lincoln IL
Apr 27, 12:00 PM Apr 27, 10:00 PM
WHAT: Flooding caused by excessive rainfall is possible.

WHERE: Portions of central, east central, and southeast Illinois,
including the following counties, in central Illinois, Christian,
Macon and Shelby. In east central Illinois, Clark, Coles,
Cumberland, Douglas, Edgar and Moultrie. In southeast Illinois,
Clay, Crawford, Effingham, Jasper, Lawrence and Richland.

WHEN: Until 10 PM CDT this evening.

IMPACTS: Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Flooding may occur in poor drainage and urban areas.

ADDITIONAL DETAILS:
- Repeated rounds of heavy thunderstorms into the evening may
result in flooding, especially in urban and low-lying areas.
- http://www.weather.gov/safety/flood
+ Read More
You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.
Updated: Apr 27, 11:59 AM Source: NWS Alert