An Ozone Exceedance = 0.071 ppm or greater
Exceedance days are unhealthy air days and shown in red in the table above.

The EPA Ozone Standard uses the Design Value: Although certainly concerning, exceedance days are not the same thing as 'violating the ozone standard'. The standard uses the 4th highest reading each year and averages it with the 4th highest readings from the two prior years. This 3-year average is called the Design Value. In the table above, the middle columns with dates show this year's 1st through 4th highest daily readings for each monitor. The 4th highest column is the one that counts at year end - the one that is averaged with the 4th highest readings from the two previous years. Each monitor's readings and averages are calculated uniquely and whichever Design Value is the highest becomes the area's Ozone Design Value.

A Violation of the ozone standard = Design Value 0.071 or greater.

Tulsa Area Ozone Alert! Days (2000 - present)

2018