No public roster classifies how each state lets you MEASURE WBGT — so we built one. Three buckets: apps and web readings accepted, on-site device required, or not specified by the association. Rows marked as primary-source verified were read against the association's or legislature's own document and date-stamped; the rest come from our research pass and deserve a call to your association before you rely on them. One more layer: your school district or county school system may impose stricter rules than the state association — in Virginia and Maryland, districts set thresholds by law.
Wildfire smoke is a separate axis from heat, with its own state policies. Three are verified so far.
| State | Measurement | WBGT mandate | Governing body | Notes |
|---|---|---|---|---|
| CA | Apps allowed | WBGT required | CIF (AB 1653) | Three regional WBGT ladders under AB 1653 and CIF Bylaw 503.K, with a hard cancel level for each. CIF requires a WBGT and, for schools without a meter, names one specific NOAA page — a single government source, not app readings in general. Guide → Primary source verified |
| FL | Device only | Conditional / preferred | FHSAA (Zachary Martin Act) | The Zachary Martin Act requires heat-stress monitoring year-round and cooling zones, and requires the reading to be measured at the site of the activity. The thresholds are FHSAA's: Policy 41 §41.8 is a practice ladder ending in no outdoor activity, and §41.9 adds a separate per-sport contest index that never stops play — see the Florida guide. Guide → Primary source verified |
| GA | Device only | WBGT required | GHSA | On-site calibrated instrument required at each practice — see the Georgia guide. Guide → Primary source verified |
| IA | Device only | Conditional / preferred | IHSAA/IGHSAU/IHSMA/IHSSA | WBGT is recommended (not mandated) year-round above 80 °F, readings every 30 minutes; marching band and cheer have their own rows — see the Iowa guide. Guide → Primary source verified |
| KY | Device only | Conditional / preferred | KHSAA | Four WBGT bands for contest alterations with a hard stop at the top, re-checked every 30 minutes. Football must measure at the competition site with no off-site measurement permitted; cross country, field hockey and soccer get the same rule as a strong recommendation, and the all-sports column sets no measurement-location rule at all. The document covers contest alterations only — a general duty to use WBGT was not found in it. Read from a web-archive capture; khsaa.org answers nothing, so currency is unconfirmed. Guide → Primary source verified |
| LA | Confirm with association | WBGT required | State law | Legislated WBGT-based rules. Research pass — confirm locally |
| MA | Device only | WBGT required | MIAA | One statewide MIAA policy covering practice AND competition, with thresholds well below most states — outdoor activity stops in the 86s. An on-site WBGT instrument is required at each activity, and a footnote says games should not occur in any sport whose protective equipment has to be modified at that WBGT band. Guide → Primary source verified |
| MD | Confirm with association | Conditional / preferred | MPSSAA | MPSSAA delegates to district policies; WBGT and heat index both appear. Research pass — confirm locally |
| MO | Confirm with association | Conditional / preferred | MSHSAA | MSHSAA: WBGT must be utilized above 80 °F air temperature (2025 update); field-oriented wording. Research pass — confirm locally |
| NC | Device only | Conditional / preferred | NCHSAA | Current handbook calls for a scientifically approved device, read hourly from 30 minutes before practice; §2.3.3(g) makes the containing policy mandatory. Stricter threshold family than most states — see the North Carolina guide. Guide → Primary source verified |
| NJ | Confirm with association | WBGT required | State law | Legislated heat participation rules since 2020. Research pass — confirm locally |
| NY | Apps allowed | Heat index based | NYSPHSAA | NYSPHSAA's procedure is written against both scales, and they are not read the same way: a heat-index ladder it tells schools to look up from a named weather app by ZIP code, and a WBGT chart in three regional categories that is read with an indicator on the field. Which category a school is in cannot be determined — the lookup NYSPHSAA links is gone — so all three are shown; see the New York guide. Guide → Primary source verified |
| SC | Device only | WBGT required | SCHSL | Schools are required to own and use an on-site WBGT thermometer; "phone apps are not scientifically approved". Range-hold rule locks in restrictions — see the South Carolina guide. Guide → Primary source verified |
| TN | Apps allowed | Conditional / preferred | TSSAA | Each school reads either WBGT or heat index; a phone app is permitted for heat index only, as a last resort. Marching band not covered — see the Tennessee guide. Guide → Primary source verified |
| TX | Apps allowed | WBGT required | UIL | Effective 2026-08-01; covers athletics and marching band. Class 2/3 regional thresholds — see the Texas guide. Internet WBGT resources are explicitly allowed; no approval list is published. Guide → Primary source verified |
| VA | Device only | WBGT required | §22.1-271.10 (school boards) | Code §22.1-271.10 (2025) requires every school board to adopt WBGT-based policies with at least five tiers and to keep them consistent with the governing athletic body's WBGT guidelines — and the VHSL publishes a statewide six-level table whose top level stops outdoor activity. Divisions still set the numbers that bind them. The VHSL does regulate the method: forecasts and apps may guide planning and "should never replace" the on-site real-time evaluation — see the Virginia guide. Guide → Primary source verified |
This table is a navigation aid, not legal advice. Policies change midseason; the association's current document controls. Found an error? Tell your athletic trainer first, then us.
wbgtcheck.com is an independent tool. It is not affiliated with, endorsed by, or connected to the UIL, GHSA, NFHS, NATA, or any state athletic association.