Tulsa, OK Air Quality Index (AQI) Today

Tulsa is one of the few metros on this site where ozone, not fine particulate, is the pollutant that decides the page. Some of the raw material for it comes off one stretch of riverbank. A refinery has run in west Tulsa on the Arkansas River, southwest of downtown, since 1913, operated now by HF Sinclair, and it releases nitrogen oxides and volatile organic compounds into the same air as the traffic crossing the river bend.

Ozone is not emitted directly. It is manufactured in the air when those precursors react under strong sunlight, which is why the bad days here are hot, light-wind July and August afternoons rather than cold winter mornings. The region built its response around that timing. INCOG put the Ozone Alert! program together over two weeks in the summer of 1991 and describes it as the first such program in the country; the state DEQ forecasts high-ozone days and the notice goes out across the five-county Tulsa area — Tulsa, Creek, Osage, Rogers and Wagoner — so employers and drivers can cut emissions voluntarily on the days that count.

What the number cannot convey is how ordinary the sky looks while it climbs. Ozone is invisible, and the conditions that manufacture it are the same conditions that produce a cloudless afternoon. A bad ozone day in Tulsa looks like a good one.