UIL Class 2 vs. Class 3: Which WBGT Thresholds Apply to Your School?

A County-by-County Guide to Texas UIL Heat Stress Classifications for the 2026-27 School Year

Starting August 1, 2026, every Texas UIL school conducting outdoor athletics or marching band activities must monitor Wet Bulb Globe Temperature (WBGT) and follow the corresponding activity guidelines. But not all Texas schools follow the same numbers.

The UIL divides Texas into two classifications — Class 2 and Class 3 — because the state's climate varies dramatically from west to east. A school in El Paso operates in fundamentally different heat stress conditions than one in Beaumont, even on days when the thermometer reads the same temperature. The classification system accounts for that difference.

Here is exactly how to determine which class your school falls under — and what that means for every flag level on the UIL activity chart.

Why Two Classifications? The Climate Case for Regional Thresholds

WBGT is a composite measure that accounts for humidity, wind, and solar radiation — not just air temperature. And in Texas, humidity is the most consequential variable. West Texas and the Panhandle are characterized by low relative humidity even during summer heat events, which means the body can cool itself more efficiently through evaporation. Athletes in Lubbock or Amarillo face a meaningfully different physiological heat stress load than athletes in Houston or Corpus Christi at the same air temperature.

This is not a subtle difference. On a 95°F day, a Lubbock afternoon at 20% relative humidity may produce a WBGT in the low 80s. The same temperature in Houston at 75% humidity can push WBGT into the Red-1 zone — a range where the UIL restricts athletes to no protective equipment and limits total practice time to one hour.

The UIL's two-class system recognizes this reality by setting lower modification thresholds for Class 2 schools. West Texas athletes may experience fewer extreme flag days overall, but they are not exempt from protection — and the thresholds still apply the moment WBGT reaches those levels.

Class 2: West Texas and the Panhandle

Class 2 covers schools in the western and northwestern portions of Texas — the Panhandle, the Trans-Pecos region, the South Plains, and parts of the Edwards Plateau. These regions share a semi-arid to arid climate profile with characteristically low humidity.

For Class 2 schools, the UIL activity chart modification thresholds are:

The Class 2 Green threshold of 79.7°F means that modification protocols are triggered earlier than they would be for a Class 3 school — but the intent is the same: protect athletes before conditions become dangerous, not after.

Class 2 Counties — Panhandle and South Plains

The following counties are among those falling under Class 2 classification. This list covers the primary Panhandle and South Plains region:

Armstrong, Bailey, Briscoe, Carson, Castro, Childress, Cochran, Collingsworth, Crosby, Dallam, Dawson, Deaf Smith, Dickens, Donley, Floyd, Garza, Gray, Hale, Hall, Hansford, Hartley, Hockley, Hutchinson, King, Lamb, Lipscomb, Lubbock, Lynn, Moore, Motley, Ochiltree, Oldham, Parmer, Potter, Randall, Roberts, Swisher, Terry, Wheeler, Yoakum.

Class 2 Counties — West Texas and Trans-Pecos

The Trans-Pecos and surrounding western counties also fall under Class 2:

Andrews, Brewster, Crane, Culberson, Ector, El Paso, Gaines, Glasscock, Howard, Hudspeth, Jeff Davis, Loving, Martin, Midland, Pecos, Presidio, Reeves, Sterling, Upton, Ward, Winkler.

Class 3: All Other Texas Schools

Class 3 applies to the majority of Texas UIL schools — the eastern two-thirds of the state, including the Gulf Coast, the Hill Country, Central Texas, North Texas, East Texas, and South Texas. These regions experience significantly higher humidity during the summer months, which substantially elevates the physiological heat stress on athletes.

For Class 3 schools, the UIL activity chart modification thresholds are:

The Class 3 Green threshold is 82.0°F — a full 2.3 degrees higher than Class 2. For schools in Dallas, San Antonio, Austin, Houston, or anywhere along the Gulf Coast, this means the modification threshold is reached less often in terms of raw WBGT reading — but the actual heat stress those athletes face on August afternoons is substantially higher than what Class 2 schools typically experience.

The Same Day, Two Different Outcomes: A Real-World Example

Consider a Tuesday afternoon in early August. Both a school in Lubbock and a school in Houston record the same air temperature: 97°F. But the WBGT readings look completely different.

Same temperature. Completely different heat stress reality — and completely different required protocols. This is exactly what WBGT is designed to capture, and why the UIL uses it rather than a simple thermometer reading.

Lubbock's Yellow flag at 81°F still requires increased monitoring and rest breaks. But the Houston school at 91°F is under Red restrictions that limit practice to one hour, prohibit protective equipment, and ban all conditioning. The thermometer, read alone, would give no indication that these two programs face different situations.

How to Look Up Your County Classification

If you are uncertain which class applies to your school, the UIL publishes the complete county-by-county classification list in its Heat Stress & Athletic Participation documentation, available at uiltexas.org. Your county of record determines your class — not your region, district, or conference.

For schools located near classification boundaries — for example, schools in Concho, McCulloch, or Coleman counties on the western edge of the Hill Country — verify directly against the UIL's official county list rather than assuming based on geography. Some boundary counties have specific designations that may not match intuitive expectations.

Frequently Asked Questions

What if our school is located in a Class 2 county but practices at a Class 3 location?

Your classification is determined by your school's county of record, not the location of a specific practice. If your county is Class 2, you follow Class 2 thresholds — regardless of where a scrimmage or away game takes place.

Do the classifications change year to year?

The current classification structure is tied to the UIL's geographic climate assessment. Changes would require UIL action. For the 2026-27 school year, the classifications are as established in the UIL Heat Stress & Athletic Participation Plan.

Does marching band follow the same class thresholds as athletics?

Yes. The UIL's heat stress mandate explicitly covers outdoor marching band rehearsals. Band directors follow the same WBGT thresholds as athletic coaches — including the same flag levels, the same modification protocols, and the same recordkeeping requirements.

Can a school voluntarily adopt more conservative thresholds?

Yes. Schools and districts can adopt thresholds more conservative than the UIL minimum. A Class 3 school may choose to begin modifications at 80°F instead of 82°F if their athletic trainer or administration determines that is appropriate. The UIL thresholds represent the minimum required standard — more protective policies are permitted.

What WBGT monitoring equipment can we use?

The UIL specifies that WBGT must be measured using a scientifically proven method with an actual black globe thermometer component — weather apps that estimate WBGT from air temperature and sky conditions do not meet this standard. Schools need an on-site instrument capable of measuring all four WBGT inputs: air temperature, relative humidity, wind speed, and globe temperature. Shop Kestrel Instruments WBGT Heat Stress Solutions: https://kestrelinstruments.com/prevent-heat-stress

For the full UIL activity chart and official county classification list, visit uiltexas.org/health/info/heat-stress-and-athletic-participation.

Sources & References

UIL Heat Stress & Athletic Participation Plan: uiltexas.org/health/info/heat-stress-and-athletic-participation

UIL Legislative Council Meeting Results, June 10, 2026: uiltexas.org/press-releases

American College of Sports Medicine — Environmental and Occupational Heat Stress Guidelines

Korey Stringer Institute, University of Connecticut — State-by-State Heat Safety Policy Analysis