Football, cross country and marching band practices at Clear Lake, Clear Brook and Friendswood high schools now operate under mandatory heat-monitoring rules that could shorten workouts or push them past sundown during the hottest weeks of August.

The University Interscholastic League's first required Wet Bulb Globe Temperature protocol took effect Aug. 1, replacing guidelines that had been voluntary since 2023. Every UIL member school must now track real-time WBGT readings before and during outdoor practices and adjust schedules accordingly.

The timing matters: the National Weather Service puts the Houston area's average August WBGT between 85 and 95, a range that triggers mandatory modifications on most practice days. With the region forecast to hit highs near 100 degrees through the weekend of Aug. 22-23, coaches across Clear Creek ISD and Friendswood ISD are already navigating the new thresholds.

What the numbers mean

Under the UIL's tiered system for the Houston/Clear Lake climate zone, according to Houston Public Media:

  • WBGT under 82: Full three-hour practice, no modifications.
  • 82 to 87: At least three four-minute rest breaks per hour, plus an on-site rapid-cooling station such as an ice bath.
  • 87 to 90: Practice capped at two hours, four rest breaks per hour, football players restricted to shorts.
  • 90 to 92: One hour max, no pads or helmets, no conditioning drills.
  • Above 92: Practice moves indoors or is canceled.

Perry Weather data from last summer found that in the Houston region, eight days hit the threshold requiring no outdoor workouts at all, 13 days fell in the one-hour limit range and 23 days landed in the two-hour cap. The most restrictive readings clustered between 11 a.m. and 5 p.m.

Why WBGT, not heat index?

WBGT factors in air temperature, humidity, wind speed, sun angle and cloud cover. National Weather Service meteorologist Jimmy Fowler told Houston Public Media on Aug. 3 that standard heat index "is only factoring air temperature and humidity and it's assuming you are in the shade." For athletes running drills in direct sun, WBGT gives a more accurate picture of heat stress.

Practices, not games

UIL Executive Director Jamey Harrison told Houston Public Media on Aug. 3 that the mandate targets practices because that is where every recent heat-related death in Texas high school athletics has occurred. A typical football player, Harrison noted, is engaged in only six to eight minutes of high-exertion activity during an entire game, compared with sustained effort over hours of practice.

"We're not saying schools can't practice," Harrison said. "We're largely talking about a 2- to 3-hour window on some days. Just don't put your kids out there in full pads with no restrictions from 4-5:30, 6 [p.m.]."

The backstory

The UIL board voted in June 2026 to make the WBGT protocol mandatory after three years as a recommendation. The decision followed heat-related tragedies including the August 2025 death of 15-year-old Preston Malone III, a sophomore JV football player at Lancaster Early College High School who collapsed from exertional heat stroke during practice. A 17-year-old Cypress Springs High School student also fell into a coma from heat stroke during a private training session last summer.

Space City Weather meteorologist Eric Berger wrote in an Aug. 19 post that average August temperatures in Texas are 1 to 3 degrees Fahrenheit warmer than a generation ago. "This is a great move that protects our kids from dangerous heat exposure," Berger wrote, "and the UIL is to be commended for using the best available science to guide decision-making."

A Houston Chronicle survey, as reported by Houston Public Media, found nearly 80 percent of local high school football coaches consider the requirement too restrictive. Texas joins at least 17 other states that now require WBGT readings to guide outdoor practices.

Schools are not required to buy their own WBGT meters; the UIL directs districts without a gauge to use free online readings from the University of North Carolina's WBGT forecasting tool.

The rules apply to all fall sports and marching band at Clear Lake, Clear Brook and Friendswood. The next test comes the weekend of Aug. 22-23, when triple-digit heat is expected to push WBGT readings well above the two-hour practice cap during afternoon hours.