Defining Extreme Heat as a Hazard: A Review of Current State Hazard Mitigation Plans

Heat is the leading cause of weather-related death in the United States. Each US state must have a FEMA-approved state hazard mitigation plan (SHMP) to be eligible for certain non-emergency disaster funds and funding for mitigation projects. Many US states are in the process of updating their plans; however, a review of each SHMP as it exists now reveals the challenge states face in adequately incorporating heat as a hazard. This report assesses the treatment and definition of heat as a hazard in each state’s plan. Furthermore, it offers supplemental information for states in parallel with the latest FEMA guidance for SHMPs that went into effect April 19, 2023.

This analysis found that the importance of extreme heat is often understated in plans. Only 25 states had a dedicated section for extreme heat, with 18 having heat combined with cold or drought. Current FEMA guidelines for SHMPs would be strengthened by further modernization of existing risk identification processes. This is critical for extreme heat since it is rarely defined by discrete events and is instead chronic and subtle. The latest FEMA guidance is more specific in requiring climate change to be factored into hazard identification. However, current state plans do not adequately incorporate climate change when addressing extreme heat.

This report offers four specific recommendations that provide a roadmap for states to adequately assess the effects of extreme heat:

• Defining heat as a hazard by combining climate and health outcome data
• Accounting for the hazard-specific vulnerabilities of their population
• Incorporating climate change
• Developing appropriate and feasible mitigation strategies