There is no national high school heat standard. Each state's athletic association sets its own policy, which means the same WBGT reading on the same device can require three different things depending on which side of a state line you are standing on.
The direction of travel is consistent: from heat index to WBGT, and from recommendation to requirement. The detail is not. States differ on the threshold values, on whether the chart is statewide or regional, on how often readings are taken, on whether apps are accepted, on whether marching band is covered, and on whether anything happens to a school that ignores the rule.
Where the thresholds diverge
The top of each chart, side by side. This is the band where the differences actually change what happens at practice.
| State | Practice stops at | The band below |
|---|---|---|
| Georgia (GHSA) | Over 92.0°F | 90.0 to 92.0°F: 1 hour, no protective equipment, no conditioning, 20 min rest |
| Florida (FHSAA) | 92.1°F and above | 90.1 to 92.0°F: 1 hour, five 4-minute breaks, no equipment, no conditioning |
| Texas (UIL) | Varies by region | Thresholds are set by region of the state; see the UIL page |
| North Carolina (NCHSAA) | 90.0°F and above | 88.0 to 89.9°F: pads and equipment off, constant observation, break every 15 min |
| South Carolina (SCHSL) | Over 92.1°F | 90.0 to 92.0°F: 1 hour, no protective equipment, no conditioning, 20 min rest |
| Tennessee (TSSAA) | Above 92.0°F | 90.0 to 92.0°F: 1 hour including 20 min rest, no conditioning |
| Oklahoma (OSSAA) | Region 3 over 92.1°F, Region 2 over 89.8°F | Two regional charts, roughly 2 to 3°F apart at every band |
| Mississippi (MHSAA) | Above 92°F | Above 90°F: 1 hour, no pads |
North Carolina is the outlier worth noticing. It suspends practice at 90°F where most states run to 92°F, and at 88°F it already requires pads off, where the Georgia-derived charts still permit helmets and shoulder pads. If you coach near that border, the chart in your head is wrong by two degrees at the point where it matters most.
Does your state accept an app for the reading?
This is the question most often asked and most often answered wrongly, because the answer genuinely differs by state. Several policies name the answer explicitly.
| State | Apps accepted? | What the policy says |
|---|---|---|
| Oklahoma | Yes, explicitly | Permits internet-based weather station software or applications, and names acceptable products and phone apps |
| Mississippi | Yes | Schools were pointed to free smartphone apps so specialised equipment would not be needed |
| South Carolina | No, explicitly | States that phone apps are not scientifically approved at this time, and that weather apps should not be relied on for a venue reading |
| Georgia | No | Requires a scientifically approved instrument that measures WBGT at each practice |
| Florida | No | Specifies an on-site device with placement, height and acclimatization requirements |
| Tennessee | Check locally | Prefers WBGT, permits heat index as a fallback where no instrument is available |
Where an on-site instrument is required, that is the right call for the compliance reading: a device on your field sees your surface, and a weather-derived number describes the air at your coordinates. Use an app for planning and forecasting in those states, not for the record.
Other ways the policies differ
| Feature | Where it shows up |
|---|---|
| Reading interval | Every 30 minutes in Georgia, Florida, South Carolina and Oklahoma. Every hour in Mississippi. |
| Regional thresholds | Texas and Oklahoma split the state into regions. Georgia, Florida and the Carolinas use one statewide chart. |
| Marching band covered | Texas and Oklahoma include marching band explicitly. Most athletic policies do not mention it. |
| Contest rules written out | Florida sets per-sport contest modifications in policy. South Carolina and Oklahoma specify football hydration breaks. Most states leave games to judgment. |
| Cooling required regardless of reading | Florida requires a cooling zone with cold-water immersion at every outdoor session, with no threshold attached. |
| Financial penalty | Georgia fines schools $500 to $1,000 for violating the heat policy. Most associations specify no penalty. |
| Device recalibration | South Carolina requires recalibration every two years, or sooner per the manufacturer. |
| Backed by state law | Florida, through the Zachary Martin Act. Most policies are association rules only. |
If your state is not listed
These pages cover the states whose published policies set out specific WBGT thresholds that could be verified against the association's own document. Several other associations require or recommend WBGT without publishing a threshold table in a form that can be summarised reliably, and some are mid-revision.
Rather than reproduce numbers that might be wrong on a heat safety page, we have left those out. To find your own: search for your state association's name plus "heat policy" and look for a document hosted on the association's own domain, not a summary. Check the revision date, because several associations have changed their policies in the last two seasons, and a coach working from a memory of the old rules is a common failure mode.
If a policy here looks out of date against your association's current document, the current document is right and we would be glad to hear about it.
What good practice looks like in any state
The thresholds differ. These do not.
A reading at the field
At the practice surface, in the sun, before activity and at a fixed interval during it, written down with the time.
Someone with authority to stop
Named in the policy, usually the athletic trainer, able to modify or end practice without negotiating with a coach.
A heat acclimatization period
Graded practice length, equipment and double sessions across the first days of preseason, which is when heat illness actually happens.
Cold-water immersion, filled before it is needed
On the field, staffed, from roughly 80°F WBGT upward. It is what makes exertional heat stroke survivable.
Warning signs of heat illness
Heat stress shows up before it becomes an emergency. Anyone on site should speak up immediately on any of these:
When in doubt, cool first and call for help. Collapse or confusion in the heat should be treated as possible exertional heat stroke: begin cold-water immersion immediately and call 911. Cooling comes before transport.
The number, in any state
Thresholds are set by your association. The reading is physics, and it is the same everywhere. The app gives you live WBGT and a 14-day forecast for any town, which is the part no state policy covers: deciding next week's schedule before the heat arrives.
- Real-time WBGT for your location or any city
- Hourly and 14-day WBGT forecasts to plan ahead
- Color-coded flag levels with mode-specific guidance
- Humidity, wind, sun and cloud cover behind every reading
WBGT is estimated from weather data with the peer-reviewed Liljegren model. Where a policy requires on-site measurement, use the app for planning and as a cross-check alongside your instrument.
Common questions
Which states require WBGT for high school sports?
A growing number, including Georgia, Florida, Texas, North Carolina, South Carolina, Tennessee, Oklahoma and Mississippi. Policies are set state by state, so check your own association's current document rather than assuming a neighbouring state's rules apply.
Are state WBGT thresholds the same everywhere?
No. Most southeastern states use a chart derived from Georgia's By-Law 2.67 with bands at 82, 87, 90 and 92°F, but North Carolina uses a different and stricter scale that suspends practice at 90°F, and Texas and Oklahoma set thresholds by region.
Can I use a WBGT app to meet my state's requirement?
It depends entirely on the state. Oklahoma explicitly permits internet-based applications and names acceptable apps, and Mississippi pointed schools to free smartphone apps. South Carolina states that phone apps are not scientifically approved, and Georgia and Florida specify an on-site instrument.
Which state has the strictest high school heat policy?
On thresholds, North Carolina, which suspends practice at 90°F WBGT and bars unconditioned athletes from 85°F. On required equipment and procedure, Florida, which mandates a cooling zone with cold-water immersion at every outdoor session and is backed by state law.
Do any states fine schools for heat policy violations?
Georgia does, with a fine of $500 to $1,000 for violating By-Law 2.67. Most state heat policies specify no financial penalty, relying on the policy being followed as a condition of membership.
Do state heat policies cover marching band?
Usually not, which is a significant gap given band rehearses on asphalt in uniform with no athletic trainer present. Texas and Oklahoma are the clearest exceptions, covering marching band explicitly alongside athletics.
Related WBGT guides
Know the real heat number
Real-time WBGT, flag levels and forecasts. Free on iPhone.
