Agency Links
IN.gov Links
Gov. Eric J. Holcomb
Eric J. Holcomb
Eric J. Holcomb
Visit His Homepage

PM-2.5 (Local Conditions) Hourly Averages

Particle pollution (also called particulate matter or PM) is the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small, they can only be detected using an electron microscope. Particle pollution includes inhalable coarse particles, with diameters larger than 2.5 micrometers and smaller than 10 micrometers and fine particles, with diameters that are 2.5 micrometers and smaller. How small is 2.5 micrometers? Think about a single hair from your head. The average human hair is about 70 micrometers in diameter -- making it 30 times larger than the largest fine particle. These particles come in many sizes and shapes and can be made up of hundreds of different chemicals. Some particles, known as primary particles, are emitted directly from a source, such as construction sites, unpaved roads, fields, smokestacks or fires. Others form in complicated reactions in the atmosphere of chemicals such as sulfur dioxides and nitrogen oxides that are emitted from power plants, industries and automobiles. These particles, known as secondary particles, make up most of the fine particle pollution in the country.

Fine particulates (PM-2.5) are generally emitted from activities such as industrial and residential combustion and from vehicle exhaust. Fine particles are also formed in the atmosphere when gases such as sulfur dioxide, nitrogen oxides, and volatile organic compounds, emitted by combustion activities, are transformed by chemical reactions in the air. Large-scale agricultural burning or sand storms can produce huge volumes of fine particulates. PM-2.5 data is the near real-time measurement of particulate matter 2.5 microns or less in size from the surrounding air. This measurement is made at local conditions, and is not corrected for temperature or pressure.

Use the controls below to select a different date or parameter and to control cell highlighting based on measured PM-2.5 (Local Conditions) levels. Click on the Generate Report button once you have made your selections.

Click on the Plot Data button once the tabular report has been generated to open a separate window containing data plots.
Select a date: Time Format: Select a Parameter:
PM-2.5 (Local Conditions) Highlights:  Moderate   Unhealthy for Sensitives   Unhealthy   Very Unhealthy   Hazardous  
Highlight validated data (Validated data has been manually reviewed by a data validator)
Select a Region:

PM-2.5 (Local Conditions) Hourly Averages for Wednesday, September 23, 2020.
measured in micrograms per cubic meter (local conditions)
Mid 1:00 2:00 3:00
North West - all times are in CST
83 13.55 FEW NA NA 83 3 IDEM
86 14.7813.01 NA NA 86 3 IDEM
Mid 1:00 2:00 3:00
North Central - all times are in EST
5 27.8329.05 FEW NA 5 3 IDEM
72 13.30 FEW NA NA 72 3 IDEM
Mid 1:00 2:00 3:00
North East - all times are in EST
7 13.30 FEW NA NA 7 3 IDEM
70 6.93 FEW NA NA 70 3 IDEM
Mid 1:00 2:00 3:00
West Central - all times are in EST
9 29.95 FEW NA NA 9 3 IDEM
27.59 FEW NA NA 4 IDEM
51 17.80 FEW NA NA 51 3 IDEM
Mid 1:00 2:00 3:00
East Central - all times are in EST
35 14.3113.72 FEW NA 35 3 IDEM
42 16.4814.35 FEW NA 42 4 IDEM
55 11.1712.37 FEW NA 55 3 IDEM
69 13.97 FEW NA NA 69 3 IDEM
77 11.63 FEW NA NA 77 3 IDEM
78 12.8714.07 FEW NA 78 3 IDEM
79 10.82 FEW NA NA 79 3 IDEM
81 11.05 FEW NA NA 81 3 IDEM
Mid 1:00 2:00 3:00
South West - all times are in CST
Mid 1:00 2:00 3:00
South East - all times are in EST
85 12.0111.5013.33 NA 85 3 IDEM
Maximum values for the day are bold within the table. Minimum values are bold italic.

Key to PM-2.5 (Local Conditions) Acceptable Highlight Colors:

The color-coding of the hourly PM-2.5 data is based on a 1-hour to 24-hour projection. This projection is based on statistics compiled over several years comparing the daily maximum 1-hour average to the midnight-to-midnight 24-hour average.
The table below shows the levels, color-coding, and suggested actions for both the 1-hour projection and the actual 24-hour standard.

Color Air Quality Rating 1-Hour
Actions to take
Moderate 15.5 - 35.4 12.1 - 35.4
  • No health impacts are expected when levels are within this range.
  • No special actions are required when levels are within this range.

PLEASE NOTE: This data has not been verified by the IDEM and may change. This is the most current data, but it is not official until it has been certified by our technical staff. Data is collected from IDEM ambient monitoring sites and may include data collected by other outside agencies. This data is updated hourly. All times shown are in local standard time unless otherwise indicated.