The New Normal? Adapting to Extreme Heat for More Resilient Communities

Current heat conditions map example (NOAA, National Weather Service, Esri). Image source: HEAT.gov

Is extreme heat the new normal?  

Heat waves, sweltering sun rays and record temperatures are being felt by everyone. In the wake of increasingly intense heat, there is an urgent need for resilient communities.

Read more to learn how communities should adapt.

Highlights

• • • The increasing frequency and intensity of heat across the United States underscores the urgent need for more resilient communities.
    • The Dallas/Fort Worth (DFW) metroplex in Texas endured 55 days of above 100 degree heat in 2023 alone.
    • Urban forestry and tree canopies are environment-friendly remedies for extreme heat.
    • Cities are using heat mapping to help decision makers manage risk in communities.

Prolonged Heat Is on the Rise

The average duration of heat wave seasons across 50 large United States cities is roughly 46 days longer compared to the 1960s (data source: NOAA, 2024). Image source: EPA.gov

Extreme summer heat has been steadily increasing throughout the United States. The Dallas/Fort Worth (DFW) metroplex in Texas endured 55 days of above 100 degree heat in 2023, with 21 of those days being consecutive according to the National Weather Service. In DFW, the top four greatest annual days with above 100 degree temperatures have occurred in the last 50 years. 

Projections and historical data show no signs of relief. Extreme heat is becoming frequent as intense heat waves, record-breaking temperatures and excessive heat warnings are becoming more common. 

Hazards of Heat In Our Communities

Millions of people throughout the country brace themselves for above 100 degree temperatures, and everyone is susceptible to the negative effects of heat.  

Urbanized areas experience particularly sweltering temperatures. The urban heat island effect is an extreme heat phenomenon, where “concrete jungles” such as cities experience higher temperatures than areas that have more green space and trees. 

Specific job roles and age groups are especially vulnerable, including construction and outdoor workers, elderly people and children.  

Extreme heat over the years has become more of a “shock” factor rather than a stressor. Much like how water shortages and water droughts are a shock to communities and lands, heat is becoming more serious in its impact.

Urban heat island mapping has been raising awareness of the impacts of extreme heat, which are often unevenly distributed. The National Oceanic and Atmospheric Administration (NOAA) has been funding urban heat watching efforts and a mapping campaign in more than 60 communities across the United States since 2017. 

Cities are using heat mapping methodologies to track heat in one day, which delivers science-based information that helps decision makers manage risk in communities. 

The “cool” side of heat? Heat, though widespread, can be difficult to measure and analyze. It is multidimensional and somewhat elusive, with many things playing a role in how heat is felt.

Tree canopies and waterfronts, for example, are compounding factors that affect how we feel heat. High humidity levels can make 90 degrees feel as if it were above 100 degrees. Shade and a gentle breeze can greatly reduce the intensity of the heat we feel.   

Cities are adding more green spaces to provide shade and environmentally friendly relief from heat.

Rising temperatures aren’t the only thing growing — communities all around need greater resiliency planning to properly adjust to heat increases. Incorporating natural outdoor spaces and more trees within large cities presents a double benefit, adding both beauty and temperature reduction. Urban forestry and trees provide much-needed protection and some respite from the intensity of heat.  

Addressing Extreme Heat

While there’s no such thing as a thermostat for the outdoors, communities can still dial up their investments to mitigate extreme heat.

Vulnerability Study in Action: Zephyrhills

The Zephyrhills community was examined more closely for the impacts of extreme heat. It was identified as the second focus area for the vulnerability study in central Pasco County.

Zephyrhills Sub-Focus Area Extreme Heat Vulnerability (Source: Fernleaf, 2024). (social vulnerability)

The city is largely composed of residential suburban and mixed-use commercial spaces, with very little recreation and open space. This lack of green space is a contributing factor to the heat island effect and adds to the exposure risk from extreme heat. Increases in average and extreme temperatures and heat waves are expected to lead to more heat illnesses and deaths among vulnerable populations; including low-income households and those experiencing homelessness.

Vulnerable populations need increased access to public spaces with A/C, water features and cooling stations, which are all critical to protect against extreme heat’s negative impacts.

Future land use planning for the city can support reducing the exposure to extreme heat by increasing the green space in the community. Considering tree density, impervious surface coverage and green infrastructure solutions can reduce localized heat effects.

Excessive heat is no longer an anomaly, but a persistent threat. Communities can act now to implement strategies that will help them adapt to extreme heat.

Through vulnerability studies, infrastructure planning and resilience efforts, communities can help everyone beat the heat and stay safe.

Looking for expert help? Our talented industry professionals bring years of expertise and knowledge for your projects.

Let Halff help you take the first step by contacting Senior Resilience Planner Melissa Beaudry (mBeaudry@halff.com).