The Texas Commission on Environmental Quality is issuing an Ozone Action Day for the San Antonio area today, as temperatures climb to the 100s.
According to the National Weather Service, Tropical Storm Cristobal is creating a dry and stable atmosphere above South Texas as it continues its northward trek across the Gulf of Mexico. That means no cloud cover and plenty of hot sun — prime conditions for ozone formation.
Ground-level ozone is a respiratory toxic agent that can cause acute respiratory health effects when people breathe high concentrations of it over several hours. These effects include decreased lung function and pain with deep breaths, and aggravated asthma symptoms.
Residents with pre-existing respiratory health conditions are advised to minimize their time outside. You can also help prevent ozone pollution by sharing a ride, walking or riding a bicycle, avoiding drive-through lanes, conserving energy, and keeping your vehicle properly tuned.
Temperatures are expected to remain in the 100s today and tomorrow, with the hottest conditions coming Tuesday. Forecasters say some parts of the Rio Grande Valley may climb as high as 110 for the first half of this week.