Welcome to the California Weather Policy Guide, a handy resource for the California Interscholastic Federation’s (CIF) weather policies for athletics in California. We’ve made it simple: here’s the key information you need.
Source: CIF Extreme Heat and Air Quality Policy.
To keep students, youth and athletes safe, the following are required:
CIF mandates a 5-day acclimatization period for all fall sport student-athletes before full practice begins. This applies to every athlete, including those who arrive after Day 1.
All Fall Sports — Days 1–5: No more than one on-field practice per day. Each session capped at 2 hours.
Helmets are the only protective equipment permitted. No shoulder pads, no full pads.
Helmets and shoulder pads only. No full pads.
Full pads permitted. Normal practice rules apply (subject to WBGT guidelines).
Acclimatization Goal: Gradually increase intensity and duration over 10–14 days. Schedule practices during cooler times (early morning or late evening) and allow frequent shade breaks.
California is the only state in the country where schools operate under three different WBGT heat thresholds determined by regional climate.
CIF Category 1 — Coastal & Northern California (Cancel threshold: WBGT ≥ 86.2°F): The most conservative tier, covering schools in cooler coastal and northern climates where extreme heat is less common but still dangerous. Applies to regions including Northern California, North Coast, San Francisco Section, and Oakland/Bay Area.
CIF Category 2 — Inland Valleys & Central California (Cancel threshold: WBGT ≥ 89.9°F): The mid-tier category covering inland valley and central regions that experience significant summer heat but with less extreme desert conditions. Example counties: Sacramento, San Joaquin, Fresno, Tulare, Kings, Kern (non-desert portions), Santa Cruz, Monterey, San Luis Obispo.
CIF Category 3 — Desert & Southern California (Cancel threshold: WBGT ≥ 92.0°F): The highest-tolerance tier, designed for schools in hot desert and southern California climates where extreme WBGT readings are common and athletes have greater baseline heat exposure. Full cancellation is required at 92.0°F WBGT well within the range regularly seen in inland SoCal during August preseason. Example counties: Los Angeles, San Bernardino, Riverside, San Diego, Imperial, Orange, Ventura.
Meeting AAA heat stress requirements starts with accurate data. Perry Weather’s on-site WBGT and Heat Index monitoring tracks conditions continuously, so your staff always has the information they need to make the right call.
Your heat stress policy is only as good as your ability to communicate it in the moment. Perry Weather gives your staff the AAA policy framework, real-time alerts, and forecasting they need to make confident decisions all season long.
Perry Weather automatically logs every WBGT reading so you always have a complete picture of heat conditions across every practice, every session, all year long.
The California Interscholastic Federation (CIF) encourages the use of a weather monitoring device to track Wet Bulb Globe Temperature (WBGT), which is a more accurate measure of heat stress than standard temperature readings. By using a wet bulb globe temperature monitor, trainers can follow CIF heat stress guidelines and adjust practice schedules accordingly.
By using weather monitoring software, schools can set up automated alerts for lightning, WBGT thresholds, and extreme weather. This reduces the burden of manual tracking and ensures CIF policies are enforced consistently.
Wet Bulb Globe Temperature (WBGT) is a heat-stress index used to assess the risk of heat illness during outdoor and indoor activities. Unlike standard air temperature, WBGT incorporates the combined effects of air temperature, humidity, radiant heat (such as sunlight), and air movement to better estimate the environmental heat load on the human body.
While both are used to evaluate hot-weather conditions, the Heat Index only combines temperature and humidity. WBGT considers additional environmental factors that can affect heat stress, making it a preferred tool for sports, outdoor work, military training, and other activities where heat safety is a concern.
Read more about the differences between WBGT and the heat index here.
Monitoring WBGT is essential for protecting athletes’ health and safety during outdoor practices, games, and events.
A higher WBGT reading leads to a greater risk of heat-related illnesses like heat stroke, heat exhaustion, and muscle cramps.
Heat acclimatization is your body’s natural process of adapting to hot weather.
By gradually increasing your activity level and time spent in the heat over 1–2 weeks, your body becomes better at staying cool and handling hot conditions.
This helps reduce the risk of heat-related illness and can improve comfort and performance in the heat.
Heat illness is a range of conditions that occur when the body can’t cool itself fast enough, from heat cramps and heat exhaustion to the most severe form, exertional heat stroke. It’s one of the leading causes of preventable death in high school athletes.
Classic heat illness is caused by environmental conditions such as high temperatures, humidity, direct sun, and low wind, all things that WBGT take in to account.
Heat Illness is typically preceded by Heat Stress – the strain placed on the body when it works to maintain a safe core temperature in hot conditions. Warning signs may be elevated heart rate, heavy sweating, and fatigue
Exertional heat stroke is the most severe form of heat illness and a medical emergency. It occurs when the body’s core temperature rises above 104°F due to intense physical activity.
Unlike classic heat stroke, which is driven purely by environmental conditions, exertional heat stroke is triggered by the body generating more internal heat than it can release during strenuous exercise.
Heat stroke prevention is often tied to real-time WBGT monitoring because it gives athletic trainers the data they need to modify activity before conditions become dangerous.
WBGT can be measured with a handheld device or a stationary on-site sensor. Handheld devices are portable but prone to shadows, calibration drift, and human error, and someone has to remember to take readings manually.
The gold standard is a stationary sensor with a 3.5″ black bulb, which automatically captures continuous readings and more accurately reflects the radiant heat your athletes are actually experiencing. For programs required to monitor WBGT at every practice, it eliminates the compliance risk that comes with manual methods.
Although the California Interscholastic Federation doesn’t have any set guidelines for lightning safety, here are recommendations from the National Federation of High School Activities (NFHSA) on what to do if a thunderstorm is imminent:
Assign staff to monitor local weather conditions before and during practices and contests.
Develop an evacuation plan, including identification of appropriate nearby safer areas and determine the amount of time needed to get everyone to a designated safer area.
When thunder is heard or lightning is seen*, the leading edge of the thunderstorm is close enough to strike your location with lightning. Suspend play for at least 30 minutes and vacate the outdoor activity to the previously designated safer location immediately.
Once play has been suspended, wait at least 30 minutes after the last thunder is heard or lightning is witnessed* prior to resuming play.
Any subsequent thunder or lightning* after the beginning of the 30-minute count will reset the clock and another 30-minute count should begin.
Perry Weather’s lightning detection and alerts system gives you clear, actionable instructions aligned with your lightning safety policies.
We’ll notify you as soon as lightning is detected with automated alerts. We guide you through immediate actions, keeping your athletes safe and practices on track.
Automatic alerts and real-time data for informed decision-making during critical weather events.
Know exactly when it’s safe to step out after a lightning strike with Perry Weather’s lightning countdown timers.
When a lightning strike is detected nearby, Perry Weather initiates a countdown until given the all-clear and resuming outdoor activities.
The timer resets with each subsequent strike, ensuring adherence to lightning safety protocols before resuming activities
Stay a step ahead with advanced radar and predictive lightning risk management for confident event planning and adaptive scheduling.
Get custom PA alerts and audible alarms with our lightning warning system.
Instantly broadcast alerts and safety messages automatically across your campus – no matter the weather conditions.
Strobe lights, loud alarms, and text-to-speech make sure you won’t miss lightning alerts.
It works even during power outages, ensuring continuous safety without needing a direct power source.
A safe shelter is any frequently inhabited building with four solid walls (not a dugout), electrical and telephone wiring, and plumbing, which aid in grounding the structure.
Yes. Lightning victims do not carry a residual electrical charge. However, prioritize checking for injuries and call emergency services immediately.
Responsibilities may vary, but typically coaches, athletic trainers, and officials share the responsibility for monitoring weather conditions and enforcing safety procedures.
Some policies allow for designated “safe havens” under sturdy structures like bleachers (away from metal supports) or inside enclosed vehicles with the windows rolled up. However, this is a last resort.
Watch how schools across California are using Perry Weather to comply with state weather policies and keep their campuses safe.
