Regional air quality forecast

The Texas Comission on Environmental Quality provides the latest air quality index report and the state’s official air quality forecast in table format on its website. The forecast may only be accessed within the TCEQ’s website.

The TCEQ’s forecast includes ozone, fine particulates (soot), and (very rarely) other pollutants. At times, the forecast may include some details regarding the geographic area likely to be affected by pollution episodes within the text, but there is no map.

Air quality forecasts by e-mail

Another convenient way to access forecasts of air pollution is to subscribe to an e-mail alert. There are three different ways to get e-mail alerts for air pollution.

• EPA’s Enviroflash: This method has the best forecast information, providing several days of forecasts and including several pollutants. Ozone warnings are not offered.
• Harris County Air Pollution Alerts: This method provides notices of tomorrow’s ozone watch and allows ozone warnings to be customized to a user’s specific geographic area. The system may also be used to issue special air pollution notices from Harris County Environmental Health. However, some users have reported difficulty subscribing and maintaining a subscription.
• TCEQ Ozone E-mail Alerts: This method provides notices of tomorrow’s ozone watch and today’s ozone warnings.

We recommend use of EPA’s Enviroflash for people who want to receive e-mail forecasts, and Harris County’s ozone warnings. If you feel you are not receiving the ozone warnings, we encourage you to try the TCEQ’s ozone warning emails.

Regardless of which e-mail system you may choose, the forecasts and real-time warnings supplied by each system are the same - you are not getting different opinions or interpretations. Each agency provides the data with different formats and different levels of user control.

This table allows you to select various maps and links to data sets for Houston-region air quality conditions and forecasts. National data are below.

Since most pollution emissions are relatively constant, the major factors affecting day-to-day levels of pollution are:

• local weather conditions;
• major chemical plant or refinery pollution releases; and
• transport of pollution from other areas (especially affecting fine particles).

There are some limited near real-time data available for air toxics from the TCEQ, but these data are not presented in a way that is of much use from a personal or public health perspective.

To access historical air pollution data for the Houston region, the TCEQ provides hourly data by pollutant reports (which also include weather data). More extensive pollution monitoring data archives are also available for download and analysis.

What caused the air pollution?

Major air pollution episodes affecting the Houston region are often analyzed by the Texas Commission on Environmental Quality within a few days, and may include extensive maps identifying the areas where the pollution episode originated as well as other contributing factors.

National air quality forecast

A national air quality forecast is provided by the US Environmental Protection Agency. Ozone values are scaled to the standard air quality index colors.

This forecast integrates information regarding both ozone smog and fine particulates (soot) into a single map.

This map is based on a variety of factors, and may differ slighly from the official Texas forecast.

This table allows you to select various maps and links to data sets for national air quality conditions and forecasts.

Since most pollution emissions are relatively constant, the major factors affecting day-to-day levels of pollution are:

• local weather conditions;
• major chemical plant or refinery pollution releases; and
• transport of pollution from other areas (especially affecting fine particles).

The EPA maintains an air toxics database, but these data are not available in a very timely manner. Analyzing the data requires some skill, but can be useful for understanding long-term exposure to air pollution.