Air Quality / Ozone
Houston Has an Air Quality Problem Worth Knowing About
The Houston-Galveston-Brazoria area — including Harris County — is classified as a serious ozone nonattainment zone by the EPA.
Ozone is a ground-level air pollutant. On high-ozone days, it can cause breathing problems, especially for people with asthma, the elderly, and children. The Houston area's mix of vehicle exhaust, petrochemical plants, and heat makes it one of the more ozone-affected metros in the country.
The EPA classified the six-county HGB area — including Harris County — as 'Serious Nonattainment' for the 2015 ozone standard in 2024. That is why Harris County requires an annual vehicle emissions test. TCEQ posts daily air quality forecasts at tceq.texas.gov. On Code Orange or Code Red days, limit outdoor exertion in the morning and midday hours.
Source to confirm: TCEQ – Houston-Galveston-Brazoria Ozone Attainment Status