Historical Air Quality Data

  • Ozone Exceedance Summary data provides a quick look at each year's ozone season exceedances.
  • QA'd data, that is, data that has been through the quality assurance process, is available for both ozone and particle pollution.

Use the form below to search and view historical air quality data.

Note: This data has not been through QA Analysis. The data available here is collected directly from the moritoring stations across the state. It has not been reviewed for accuracy, nor have past values been modified to reflect current advancements in pollutant calculation algorithms. Yesterday’s data is available by 10 AM today.

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On March 12, 2008 EPA promulgated a revised 8-hour standard for ground-level ozone at 0.075 ppm (75 ppb). It became effective June 12, 2008.

EPA has revised standards for particle pollution. The particle pollution standard specifically addresses particles smaller than 2.5 microns (PM2.5). The PM2.5 standard is 15 micrograms per cubic meter based on an annual average and 35 micrograms per cubic meter on a 24-hour average. In 2011 EPA is expected to propose a revised PM2.5 NAAQS.