Each day during ozone season (roughly March through November in Texas), the TCEQ informs the public when forecasted conditions can lead to Ozone Action Days. These are days when ozone levels are above normal and can impact our health through the quality of the air we breathe.
Sign-up for e-mails and text alerts about TCEQ’s Air Quality Forecast through the TCEQ newsletter page to stay in the know about ozone levels near you. It’s especially important to stay informed about Ozone Action Days during the summer months, so we can take steps to reduce pollutants contributing to ozone formation.
Ozone, sometimes referred to as smog, is a gas that is formed in the atmosphere when three atoms of oxygen combine. The chemical structure of ozone is the same wherever it is found; however, there are two categories of ozone.
Ground-level ozone is important because it is a respiratory toxic agent that can cause acute respiratory health effects when people breathe high concentrations of it over several hours. These effects can include decreased lung function and pain with deep breaths, as well as aggravated asthma symptoms.
TCEQ meteorologists make daily Ozone Action Day (OAD) forecasts for 17 major areas in Texas.
The Ozone Action Day forecast seasons are based on when each region is likely to experience elevated ozone concentrations. Each forecast predicts whether ozone levels for the following day in an area are expected to reach or exceed the EPA’s AQI Level Orange — an eight-hour average of 71 parts per billion or a one-hour average of 125 ppb.
TCEQ meteorologists use a set of criteria from historic meteorological data, ozone measurements, and ozone prediction models to make these predictions. When they forecast an Ozone Action Day, TCEQ meteorologists contact the National Weather Service, which then broadcasts the information across its “weather wire.” TCEQ also contacts officials in affected areas so that local community clean air coalitions can notify their media, government, business, and industry. Ozone Action Days are issued, in most cases, by 2 p.m. local time and are valid for the next day.
You can sign up for e-mail and text alerts about TCEQ’s Air Quality Forecast and other topics on the TCEQ newsletter page.
You can also sign up to receive e-mail alerts through the EPA EnviroFlash website.
