California is the only state on this site with three different WBGT ladders. CIF assigns each school a region category, and the same reading means different things in San Diego and in the Sierra foothills — so the number alone tells you nothing until you know your category.
Look up your school's category on the CIF roster
The policy runs under CA State Law AB 1653 and CIF Bylaw 503.K. Heat Illness and 503.L. Air Quality Index Protocols, and it splits the state into Category 1, 2 and 3 by climate. Most states fall into one category or two; California spans all three.
At the top of each ladder the language is not advisory — it is mandated for the benefit of the health and safety of our student-athletes that practice/games be canceled, or delayed until cooler when WBGT exceeds these levels.
The three categories share one set of actions and differ only in the temperatures that trigger them. Find your category in the column headers, then read down.
| Flag | Category 1 | Category 2 | Category 3 |
|---|---|---|---|
| GREEN | <76.1°F | <79.7°F | <82.0°F |
| YELLOW | 76.3 - 81.0°F | 79.9 - 84.6°F | 82.2 - 86.9°F |
| ORANGE | 81.1 - 84.0°F | 84.7 - 87.6°F | 87.1 - 90.0°F |
| RED | 84.2 - 86.0°F | 87.8 - 89.6°F | 90.1 - 91.9°F |
| BLACK | ≥86.2°F | ≥89.8°F | ≥92.1°F |
Identical across Category 1, 2 and 3 — only the trigger temperature above changes.
| WBGT (°F) | Required modifications |
|---|---|
| GREEN <76.1°F |
|
| YELLOW 76.3 - 81.0°F |
|
| ORANGE 81.1 - 84.0°F |
|
| RED 84.2 - 86.0°F |
|
| BLACK ≥86.2°F |
|
The policy states its cancel levels twice and the two do not match: the text on the first page lists one set, the chart on the next prints another. The chart also leaves gaps at most of its boundaries, not just one — Category 3 prints yellow as 82.2 - 86.9°F and orange as 87.1 - 90.0°F, so 87.0°F is printed in neither. This site resolves every one of those gaps upward — the hotter flag wins — so a reading in a disputed range is never shown as the cooler category. Your association's own chart governs; ours only errs toward stopping sooner.
The policy is direct about the instrument: "The CIF requires that schools use the WBGT for the most accurate measurement."
And then it does something no other association on this site does. For schools that do not own a meter, it names an online source: "Schools without a WBGT should use the link below from the NOAA for a WBGT reading" — linking NOAA's own WBGT map.
The NOAA WBGT map the policy links
That makes California one of the few states where an online WBGT reading is explicitly contemplated. It still does not make this site your official reading: CIF names NOAA's map, not this one. Use this to plan, and follow your school's own procedure for the reading that counts.
The policy opens with a four-step plan it describes as guidance — build intensity and duration over 10 to 14 days, teach hydration, move practices to the cooler ends of the day, and keep a whole-body cooling method at every venue.
The cooling requirement is separate from all of it and applies everywhere: "The school will have available a method to institute whole-body cooling to treat a student-athlete with exertional heat illness, especially heat stroke (e.g., ice tub, “taco tarp”, ice towels) which is easily accessible at all practice and contest venues."
What follows that plan is written in "shall", and it governs the opening week of preseason — where heat illness actually concentrates: "Preseason practice shall begin with a five-day acclimatization period for all Fall student-athletes. All student-athletes, including those who arrive at preseason practice after the first day of practice, are required to undergo a five-day acclimatization period."
Inside that period the limits are fixed: "Participants shall not engage in more than one on-field practice per day during the five-day acclimatization period. On-field practices shall last no longer than two hours."
And football adds a pad progression across the same days: "During the first three days of practice or testing activity, helmets shall be the only protective equipment student-athletes may wear. During the next two days of practice or testing activity, helmets, and shoulder pads shall be the only protective equipment student-athletes may wear. Student-athletes may practice in full pads on the sixth day of practice or testing activity."
All thresholds and quotations above were read from the CIF Constitution and Bylaws on 2026-08-10. CIF 2026-27 Constitution and Bylaws — Extreme Heat and Air Quality Policy (pp.102-104)
One caveat on the citation itself: CIF's numbering disagrees with itself. The sentence above cites 503.L for air quality, but the bylaws printed earlier in the same book put the Air Quality Index Protocol at 503.K(2) and give 503.L to Emergency Action Plans and AED Protocols. We quote CIF as written rather than renumber it, and this site's air-quality page cites 503.K(2).
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