01 · The problem
What is happening
Phoenix sits in the Sonoran Desert, and its summers are long and extremely hot. In July 2023, the city recorded an unprecedented run of consecutive days at or above 110°F (43.3°C), according to the National Weather Service. Maricopa County's public health department publishes annual heat death reports, which have documented rising heat-related deaths, with people experiencing homelessness disproportionately affected. The city created a dedicated Office of Heat Response and Mitigation in 2021.
Critical severity. Severe, persistent harm to health, ecosystems or livelihoods. Severity is descriptive editorial metadata summarising documented effects. It is not a measured index or a score.
02 · Causes
Why it is happening
- 01
Desert climate and warming
Global warming raises already extreme summer temperatures.
- 02
Urban heat island
Asphalt and buildings retain heat, keeping nights hot.
- 03
Rapid growth
Expanding development increases heat-absorbing surfaces.
03 · Impacts
Who and what it affects
- 01
Heat-related deaths
Heat is a leading weather-related cause of death in the county.
- 02
Risk to unsheltered people
People experiencing homelessness face the highest exposure.
- 03
Energy dependence
Loss of air conditioning during heat can be life-threatening.
04 · Solutions
Documented approaches
Office of Heat Response and Mitigation
A dedicated city office coordinating heat response.
Expected effectImproves planning, cooling centres and outreach.
Cool pavement and shade
Reflective pavement coatings and tree and shade programmes.
Expected effectLowers surface temperatures locally.
Cooling centres and outreach
Heat relief network and outreach to vulnerable residents.
Expected effectReduces heat exposure during extreme events.
05 · Key indicators
What can be measured
- Notable event
- Consecutive days at or above 110°F2023
July 2023 set a record for consecutive days at or above 110°F, per the National Weather Service.
06 · Sources
Where this comes from
- [1]National Weather Service PhoenixNOAA National Weather Serviceweather.gov(opens in a new tab)
- [2]Maricopa County Department of Public HealthMaricopa Countymaricopa.gov(opens in a new tab)
- [3]Office of Heat Response and MitigationCity of Phoenixphoenix.gov(opens in a new tab)
Links open the publishing organisation's site. Some point to the publisher's main page, where the named report or dataset can be found.