Air Quality Reports for Ohio's Cities

These reports contain pollution data, in hourly averages tabular form, measured across the state during the previous day. They present the data in "RAW" form, meaning that the data you see are exactly what was collected electronically from each pollution monitor every hour. Please see the note and disclaimer below.

Please select from the following reports:

  • Highest Hourly-averages Report - This report is a listing of the highest hourly average reading recorded during the previous day for each of these parameters: carbon monoxide (CO), sulfur dioxide (SO2), ozone (O3), particulate PM10, particulate PM2.5 and nitrogen dioxide (NO2), as measured at monitoring sites operated by the Ohio EPA and Local Air Agencies in Ohio.
  • Today's Air Quality Readings - This report is a listing of the hourly air quality readings recorded during the current day, as measured at air monitoring sites operated by the Ohio EPA and Local Air Agencies in Ohio. The daily average and maximum readings are also listed, along with the hour of the maximum reading.
  • Yesterday's Air Quality Readings - This report is a listing of the hourly air quality readings recorded during the previous day, as measured at air monitoring sites operated by the Ohio EPA and Local Air Agencies in Ohio. The daily average and maximum readings are also listed, along with the hour of the maximum reading.

Each of the options above will access reports of pollution data measured across the state during the previous day. These reports present the data in "RAW" form, meaning that the data you see are exactly what was collected electronically from each pollution monitor several times during each day. It is important to remember that "RAW" data are never considered valid until verified by Ohio EPA and Local Air Agency personnel, a process that can take much more time than the nearly immediate data availability on this website. Thus, data seen here may not necessarily be "FINAL" data. Please bear in mind that what you see in these reports will not always be 100 percent accurate.

Some readings will include letters or numbers in place of or after the data value, called "FLAGS." These flags indicate that something other than normal sampling occurred during that hour, such as monitor maintenance or calibration, daily diagnostic tests, performance audits, monitor malfunction, etc. Hourly readings that are blank indicate that there was no data available for that hour, usually due to monitor malfunction or a problem in communication between the monitoring site and the central computer system that retrieves the data.

The reports available in this section present data from several types of air pollution monitors. These monitors continuously sample the air to detect levels of air pollutants harmful to public health and welfare. The data collected by the monitors is then used to assess each area's compliance with the National Ambient Air Quality Standards (NAAQS), which are maximum acceptable levels of each pollutant as designated by the U.S. EPA. Some of the pollutant names, or "Parameter," along with the most common unit of measurement, or "Unit," for each, are:

Parameter Unit
Carbon Monoxide (CO) PPM (parts per million)
Sulfur Dioxide (SO2) PPB (parts per billion)
Ozone (O3) PPB(parts per billion)
Nitrogen Dioxide (NO2) PPB (parts per billion)
Particulate Matter (PM10) UG/M3 (micrograms/cubic meter)
Particulate Matter (PM2.5) UG/M3 (micrograms/cubic meter)
   

 

Groups sensitive to the effects of air pollution:

  • Particle pollution - People with heart or lung disease (such as asthma), older adults and children
  • Ground-level ozone - People with lung disease (such as asthma), and children and adults who are active outdoors

Note: Data in these reports are always referenced to Eastern Standard Time (EST). Air Quality Index reports are updated several times during a day at regular intervals (generally 15 or 30 minutes past the hour or hourly from 8 a.m. - 10 p.m.).

Disclaimer: These reports present the data in "RAW" form, meaning that the data you see are exactly what was collected electronically from each pollution monitor several times during each day. It is important to remember that "RAW" data are never considered valid until verified by Ohio EPA and Local Air Agency personnel.

The data in these reports have neither been validated nor quality assured by state or local air monitoring agencies. These data may change and are not considered official until they have undergone a quality assurance/quality control (QA/QC) review.

Odd data are suspected invalid due to possible equipment trouble or telemetry problems.