Ozone Season Returns to North Texas
Arlington, TX – Longer days and rising temperatures mark the return of spring and the start of ozone season in North Texas.
Ozone season runs annually from March 1 through Nov. 30. With higher temperatures, sunlight and heat interact with precursor pollutants volatile organic compounds (VOCs) and nitrogen oxides (NOx) creating favorable conditions for the formation of ground-level ozone, a harmful air pollutant that can negatively affect air quality and public health.
The 2025 season ended with a design value of 83 parts per billion (ppb) at two regulatory monitors in Collin (Frisco) and Tarrant (Fort Worth northwest) counties. As a result, the region remains in nonattainment of both the 2008 (75 ppb) and 2015 (70 ppb) National Ambient Air Quality Standards for ozone.
Dallas-Fort Worth is currently classified as a “severe” nonattainment zone under the Environmental Protection Agency’s (EPA) 2008 ozone standard and a “serious” nonattainment zone under the 2015 standard, with a deadline to reach compliance by 2027, based on monitor values recorded from 2024 to 2026.
Improving air quality is a shared responsibility. The North Central Texas Council of Governments (NCTCOG) offers various online resources to help individuals, businesses and local governments stay informed and take action. The 2025 Air Quality Handbook provides a full breakdown of the region’s air quality and the air quality initiatives. Learn more at NCTCOG.org/trans/quality/air.
Over 60% of emissions originate from mobile transportation sources such as cars and trucks. Staying informed about daily air quality initiatives and strategies helps individuals and businesses reduce emissions by taking small, everyday actions. Residents can sign up for air quality alerts at AirNorthTexas.org/sign-up-for-alerts.
About the Regional Transportation Council:
The Regional Transportation Council (RTC) of the North Central Texas Council of Governments has served as the Metropolitan Planning Organization (MPO) policymaking body for regional transportation planning in the Dallas-Fort Worth area since 1974. The MPO works in cooperation with the region’s transportation providers to address the complex transportation needs of the rapidly growing metropolitan area. The Dallas-Fort Worth metropolitan area includes Collin, Dallas, Denton, Ellis, Hood, Hunt, Johnson, Kaufman, Parker, Rockwall, Tarrant and Wise counties. The RTC’s 45 members include local elected or appointed officials from the metropolitan area and representatives from each of the area’s transportation providers. More information can be found at www.nctcog.org.
