Texas Commission on Environmental Quality
Air Dispersion Modeling Team (ADMT) 
AERMET Meteorological Data Version 24142
February 2026

--- File naming convention ---

In each AERMET meteorological zip file, there will be either one year or five years of processed meteorological data for your county.
 
For minor new source review air permitting requirements, one year of meteorological data is generally sufficient. The standard year for minor new source review permits modeling is 2024 (or 2020 if 2024 data are not available).    
 
There will be three pairs of pfl and sfc files for each county. One pair for each roughness category.

There will be six pairs of pfl and sfc files for Harris and Travis Counties. Meteorological datasets for two surface stations are available. The applicant will determine the appropriate surface station for the project site. Documentation on the choice of the surface station will be required to be submitted to TCEQ as part of the air permits modeling review. The documentation should include a review of the land use in the vicinity of the surface station and the project site.
 
The naming convention is:
 
Example:
 
HARRIS_IAHLCH24M.SFC
HARRIS_IAHLCH24M.PFL
 
The letters to the left of the underscore represent the county name.
The first three letters to the right of the underscore represent the surface station name: IAH = Houston Intercontinental Airport, TX.
The next three letters represent the upper air station name: LCH = Lake Charles, LA.
The next two numbers represent the year of the met data: 24 = 2024
The last letter represents the roughness parameter used: 
  L = low roughness
  M = medium roughness
  H = high roughness

The counties.xlsx spreadsheet provides the albedo and the Bowen ratio for each county as well as information identifying the meteorological stations.

The applicant will determine the appropriate surface roughness parameter category for the project site. Documentation on the choice of the surface roughness parameter category will be required to be submitted to TCEQ as part of the air permits modeling review.


--- Sources of data ---   

1-minute Automated Surface Observing Stations (ASOS) wind data for the measurement sites were obtained from the National Centers for Environmental Information (NCEI) 
website for 2020-2024.

5-minute Automated Surface Observing Stations (ASOS) wind data for the measurement sites were obtained from the National Centers for Environmental Information (NCEI) 
website for 2020-2024.

Hourly surface data for the measurement sites were obtained from the NCEI Integrated Surface Database (ISHD) for 2020-2024. 

Upper-air data were obtained from the NCEI Integrated Global Readiosonde Archive (IGRA) database for 2020-2024.

*Thirty-seven counties did not meet completeness. To address this, ADMT processed data using the year 2018 or/and 2019 for these counties to replace the year having incomplete data as applicable.