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Murrieta Valley Unified School District

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Weather Guidelines below adapted from the California Department of Public Health in alignment with website ADA accessibility WGAG 2.0 standards. Additional information may be found on the CDPH website. 

Heat Risk Grid explains levels 0 (Little/None) through 4 (Extreme). For each level it lists what the level means, who is at risk, and recommended actions.

CDPH Heat Risk Grid for School Communities. Understanding “HeatRisk” Level, Who is At Risk, and What Actions to Take
Value Risk What this means Who / What is at risk Actions to take
Level 0 — Little to None Little to None This level of heat poses little to no risk from expected heat.   No elevated risk.
  • No preventative actions necessary.
Level 1 — Minor Minor
  • Heat tolerated by most.
  • Minor risk for extremely heat-*sensitive groups.
 Primarily those who are extremely *sensitive to, especially when outdoors without cooling or hydration.
  • Increase hydration;
  • Reduce time outdoors or stay in the shade when the sun is the strongest. 
Level 2 — Moderate Moderate
  • Moderate risk for heat-*sensitive groups.
  • Some risk for general population who are exposed to the sun for longer period of time. 
 Heat-*sensitive or vulnerable groups, Those not acclimated to this level of heat. Otherwise healthy individuals exposed to longer duration heat without effective cooling or hydration. 
  • Reduce time in the sun during the warmest part of the day.
  • Stay hydrated.
  • Stay in a cool place during the heat of the day (10 a.m. to 5 p.m.)
  • Move outdoor activities to cooler times of the day. 
Level 3 — Major Major
  • Major risk to all individuals who are: 1. exposed to the sun & active or 2. are in a heat-*sensitive group.
  • Dangerous to anyone without proper hydration or adequate cooling. 
 Much of the population, especially anyone without effective cooling or hydration. Those exposed to the heat/sun at outdoor venues. 
  • Cancel outdoor activities during the heat of the day (10 a.m. to 5 p.m.).
  • Move activities to the coolest part of the day. 
  • Stay hydrated.
  • Stay in a cool place especially during the hear of the day and evening. 
Level 4 — Extreme Extreme
  • Extreme risk for the entire population.
  • Very dangerous to anyone without proper hydration or adequate cooling.
  • This is a multi-day excessive heat event.
 Entire population exposed to the heat is at risk. For people without effective cooling, especially  heat sensitive groups, this level of heat can be deadly.
  • Cancel outdoor activities.
  • Stay hydrated.
  • Stay in a cool place.

*Populations at higher risk of heat-related health impacts include older adults, young children, unhoused residents, those with chronic health conditions, outdoor workers, those exercising or doing strenuous activities outdoors during the heat of the day, pregnant individuals, those living in low-income communities, and more. ** For Extreme (Magenta/4) and Major (Red/3) risk levels, CDPH recommends more caution and therefore guides canceling outdoor activities based on these scenarios.