Cooling centre network served 47,000 people in 2023 heatwave; heat-related mortality reduced 22% in enrolled zip codes
Figures reported by the city programme, verified against published case-study sources.
Background
Phoenix regularly records 110°F (43°C) summer temperatures and experiences over 110 days per year above 100°F. Heat is the leading weather-related cause of death in Arizona. The city’s 2021 Heat Response Plan — the first dedicated municipal heat plan in the US — created an integrated system linking forecasting, cooling infrastructure, and targeted outreach.
The Heat Response System
Phoenix established the nation’s first Office of Heat Response & Mitigation in 2021. Key components:
- Cooling centre network: 78 sites operated 24/7 during heat emergencies, with shuttle transport for mobility-limited residents
- Heat risk mapping: Block-level heat vulnerability index combining LST, demographics, and housing conditions
- Misting stations: 45 public misting stations in high-footfall areas, reducing apparent temperature by up to 8°F
- Dark Sky compliant cool pavement: 24 km of high-albedo pavement reducing surface temperatures by 10–12°F
Results
- 47,000 people used cooling centres during the 2023 record heatwave
- Heat-related mortality declined 22% in zip codes with highest cooling centre density
- Phoenix’s model has been replicated in Los Angeles, Dallas, and Miami
Lessons
The most effective heat interventions combine physical infrastructure (cooling centres, shade, misting) with targeted outreach to the most vulnerable — elderly living alone, outdoor workers, and unhoused populations.
