Skip to main content

Latest Hourly PM-2.5 Levels for Houston Metropolitan Area

The map below shows the latest 1-hour PM-2.5 average for each monitoring site in the Houston Metropolitan Area measured in micrograms per cubic meter (local conditions) (µg/m³ LC). The background color in each box represents the relative quality of the air based on the level of PM-2.5 that is being measured at each site. To see all of today's measurements from a site click on its box.

Hourly PM-2.5 may be measured two different ways, which vary on the amount of time over which the hourly data is compiled and available. The "PM-2.5 (Local Conditions)" parameter is obtained as a single hourly average from the monitoring site, while the "PM-2.5 (Local Conditions) Acceptable" parameter hourly average is compiled from smaller increments of measurements. As such, the "PM-2.5 (Local Conditions} Acceptable" hourly average for a particular hour is displayed before the "PM-2.5 (Local Conditions)" hourly average for that same hour.

Current PM-2.5 1-hour levels are normally updated once an hour. The map below shows the areas where TCEQ is actively monitoring PM-2.5.

Sites outside the Houston Metropolitan Area will appear dimmer than sites within the area. You can still select these sites to see data collected at them.

PLEASE NOTE:  This data has not been verified by the TCEQ and may change. This is the most current data, but it is not official until it has been certified by our technical staff. Data is collected from TCEQ ambient monitoring sites and may include data collected by other outside agencies. This data is updated hourly. All times shown are in local standard time unless otherwise indicated.

Following EPA reporting guidelines, negative values may be displayed in our hourly criteria air quality data, down to the negative of the EPA listed Method Detection Limit (MDL) for the particular instrument that made the measurements. The reported concentrations can be negative due to zero drift in the electronic instrument output, data logger channel, or calibration adjustments to the data. Prior to 1/1/2013, slightly negative values were automatically set to zero.