Extreme Weather and Public Health

Extreme Heat Related Maps

The following maps reflect the ongoing work of the Arizona Department of Health Services (ADHS) to visually represent the populations that may be most vulnerable to extreme heat events throughout the state. The selected indicators that are represented include: children under the age of five, elderly adults, elderly adults that live alone, and economically disadvantaged families and individuals. These social indicators have been selected after a thorough review of both public and academic reports that similarly try to visualize vulnerability to extreme heat events and heat-related illnesses in other parts of the country. We represent demographic data at both the county and census tract levels to demonstrate state-wide and more local patterns. Additionally, we have represented demographic data in absolute numbers as well as percentages of appropriate populations.

• Social Vulnerability Indicators
• Impervious Surfaces and Urbanization
• Weather-Related Variables
• National Weather Service Arizona County Warning Areas

While the distribution of demographic data is useful in examining the populations that may be most vulnerable to extreme heat events, the built, or urban, environment may also contribute to the vulnerability of individuals and households. We use data that reflect the distribution of impervious surfaces (examples include parking lots or concrete) to identify areas that may be most susceptible to what has been defined as the Urban Heat Island Effect. Areas with a large amount of impervious surfaces collect excess heat throughout the day and release this heat over longer periods of time. The results of the Urban Heat Island Effect include elevated air temperatures immediately surrounding the impervious surfaces as well as elevated night-time temperatures. Ultimately, the Urban Heat Island Effect can increase an individual's exposure to extreme heat, especially during an extreme heat event.

Social Vulnerability Indicators

County Level Maps

• Maps Reflecting Absolute Figures for County Populations
  • Number of children under the age of five
  • Number of elderly people who are 65 years or older
  • Number of people who are 65 years or older and live alone
  • Number of families that live below the poverty line by county
  • Number of people who live below the poverty line by county
• Maps Reflecting Percentages of County Populations
  • Percent of the population under the age of five
  • Percent of elderly people who are 65 years or older
  • Percent of people who are 65 years or older and live alone
  • Percent of families that live below the poverty line
  • Percent of people who live below the poverty line

Census Tract Level Maps

• Social Vulnerability Index Map and Methods
  • Index of Populations Vulnerable to Extreme Heat Events in Arizona
• Maps Reflecting Absolute Figures for Census Tract Populations
  • Number of children under the age of five by census tract
  • Number of elderly people 65 and older by census tract
  • Number of people 65 and older who live alone by census tract
  • Number of families that live below the poverty line by census tract
  • Number of people that live below the poverty line by census tract
• Maps Reflecting Percentages of Census Tract Populations
  • Percent of children under the age of five by census tract
  • Percent of elderly people 65 and older by census tract
  • Percent of people 65 and older who live alone by census tract
  • Percent of families that live below the poverty line by census tract
  • Percent of people that live below the poverty line by census tract

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Impervious Surfaces and Urbanization

County Level Map

• Impervious surfaces in Arizona

Census Tract Level Map

• Impervious surfaces in Arizona

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Weather-Related Variables

• Average yearly precipitation (in) and average number of days per year over 100 °F between 2001 and 2011
• Average maximum temperature and average number of days per year over 100 °F between 2001 and 2011
• Average maximum temperature and average yearly precipitation (in) between 2001 and 2011

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National Weather Service Arizona County Warning Areas

The state of Arizona is serviced by four different Weather Forecasting Offices from the National Weather Service (NWS): the Phoenix office has responsibility for southwest/south-central Arizona; Tucson forecasts for southeastern Arizona; Flagstaff covers the north-central and northeast portion of the state, and the office in Las Vegas has responsibility for northwest Arizona. When the NWS issues a Severe Weather Warning (such as a Severe Thunderstorm or Tornado Warning), it typically issues the warning for only a portion of a county, not the entire county. This is due to the fact that Arizona counties generally cover large areas and weather events typically have impacts at smaller scales.

To help you understand the geographic regions that the NWS may issue warnings for, we have included maps from the NWS that break down the state of Arizona, as well as individual counties, into well-defined subdivisions. The counties that the NWS has subdivided include: Maricopa County, Pinal County, Yuma County, Gila County, and La Paz County. Additionally, we have included the subdivisions for the metropolitan Phoenix area. It is our hope that when the NWS issues a warning these maps will help you know exactly where the warning event is occurring.

• NWS County Warning Areas for the State of Arizona
• NWS County Warning Areas for Selected Counties and Metropolitan Areas

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Note: Information provided in PDF files.