Hopkins Heat Vulnerability Study
An exploration of how Hopkins, MN is affected by a warming planet and how it can adapt to keep its residents safe from extreme heat events
Project Overview
Grant description
Minnesota is getting hotter. Hopkins is exploring how heat impacts people who live in the city and how to keep people safe. This project focuses on the Blake Road and Excelsior Boulevard corridors, which tend to be hotter than other parts of the city.
To plan for community safety in the heat, the City is working to understand how people in Hopkins currently handle the heat, what strategies people can use to stay safe during heat waves, and how the City can help people stay safe in the heat. Throughout this project, the City spoke with residents and business owners, and looked to other cities to better understand what can be done to stay safe and keep others safe in extreme heat.
This story map includes a summary of the dangers of extreme heat, locates risks within Hopkins, and provides recommendations for residents and the City to reduce risks in future heat waves.
Extreme Heat
What is Urban Heat Island Effect?
Urban heat island effect happens because of the ways cities are built — dark surface materials, like asphalt, absorb and retain heat from the sun, which warms the surrounding area and makes it harder to cool off at night. Cars, industry, and waste heat from buildings also contribute additional heat that remains trapped in the city.
On the other hand, trees, vegetation, and water bodies help keep cities cool. Urban heat islands lack these cooling amenities and can be up 15 degrees hotter than nearby areas, making extreme heat more intense and dangerous for human health.
Extreme Heat Examples
In the summer of 1995 in Chicago, over 700 people died during a five-day heat wave when temperatures reached as high as 115 degrees Fahrenheit. After the heat wave, researchers found that social isolation, socioeconomic and racial disparities, land use, and an inadequate response from city officials were the main factors that made this heat wave especially deadly. Social isolation was especially common among men over the age of 65 living alone. Since this heat wave, Chicago developed an extreme heat plan to open cooling centers, ensure wellness checks for older adults and people with disabilities, and extend outreach to people experiencing homlessness.
More recently, in the summer of 2021, a heat dome caused high temperatures across the Pacific Northwest of the United States and Canada. Over 500 people died as a result of the heat wave and similarly to Chicago, socially isolated adults were the most vulnerable. High temperatures are not common in that area of the country, making this heat wave particularly dangerous and disruptive. Many cities across the region have adopted or are developing heat adaptation and emergency response plans to prepare for future heat waves.
When the Urban Heat Island Effect is Even More Intense
The effect of urban heat island is higher in areas that were redlined — a discriminatory housing practice that contributes to racial segregation and wealth disparities.
Researchers have found that areas that were redlined were, on average, 2.6 degrees hotter than areas that were not redlined. This is because these areas tend to have more industry, pavement, and fewer green spaces due to historic underinvestment and policy decisions.
These neighborhoods are often disproportionately people of color and households with lower-income, and are at greater risk during times of extreme heat.
Heat in Hopkins
Although heat is dangerous to everyone, some people are more vulnerable to extreme heat than others.
People who are the most exposed to extreme heat are the most vulnerable to its health impacts — this includes people who work outside and people who are experiencing homelessness and live outside. Even those who can stay inside can be especially vulnerable to extreme heat if they do not have access to or cannot afford air conditioning.
Older adults are also more vulnerable to health impacts from heat because their bodies may be less able to adapt to high temperatures. People with preexisting health issues can also be at high risk for heat-related health problems.
Historic underinvestment in greenspace and trees in communities of color and low-income communities has resulted in these communities to be more susceptible to heat-related danger due to the urban heat island effect.
Heat Vulnerable Populations
The Minnesota Pollution Control Agency considers areas of environmental justice concern as census tracts where the number of people of color is greater than 50% or more than 40% of households have an income of less than 185% of the federal poverty level. The Blake and Excelsior corridors are identified as meeting those criteria.
By tying US Census Data to the project area's block groups, it becomes clear where areas of environmental justice concern currently exist located along the corridor.
Other considerations
Populations Most Vulnerable to Heat
Of the categories above, areas with over 50% of households reporting as non-white populations and areas with over 40% of households living below the poverty line are considered the most vulnerable to extreme heat.
Using the map to the right, you can explore how block groups that have medium heat vulnerability (either >50% non-white households OR >40% households living in poverty) and block groups with high heat vulnerability (BOTH >50% non-white households and >40% households living in poverty) relate to their relative land surface temperature. The hotter the land surface temperature, the warmer the color with red being the hottest identified temperature.
As you can see, the highest relative temperatures in Hopkins follow the Excelsior Boulevard/Blake Road Corridors where there is low vegetative coverage as compared to the surrounding areas. See why in the next section.
Why is this Corridor So Hot?
The land surface temperature is determined by a ratio of heat generating and heat abating land covers.
Currently, the project area is primarily composed of heat generating surface types (i.e. buildings, roads/paved surfaces, etc.), which greatly contributes to the area's high land surface temperature.
A large swath of land is currently under construction for the METRO Green Line Extension, which has reduced the amount of heat abating land cover in the project area from what is shown to the right. Until newly planted greenspace has time to re-establish, the area identified in the diagonal hatch must also be considered as heat generating land cover.
Developing Recommendations
The following recommendations were developed based on best practices that have emerged from other cities across the country, as well as conversations with community members and businesses along the corridor.
What Cities Across the Country are Doing to Beat the Heat
Cities can provide support for people during the heat by planning ahead, providing support to people when it’s already hot, and strengthening infrastructure that is especially important during natural disasters.
Tree Giveaway Event (Image Credit: Tacoma Tree Foundation)
Washington, DC, Tacoma, and Tempe have all developed plans for extreme heat. Washington, DC created a heat response plan based on community engagement and input.
Tacoma, Washington pays people to plant trees on private property. Tempe, Arizona has hired an emergency manager to handle extreme weather, including heat.
Heat Mapping Study (Image Credit: King County)
Chula Vista, California has replaced traditional concrete with cool pavements and installed cool roofs to decrease urban heat island effect.
Chicago, Illinois' heat emergency response plan has been in place for years. When the temperatures rise above 105 degrees, the City opens cooling centers and cooling buses. King County, Washington has changed their emergency response to include alerts in multiple languages.
Extremely hot temperatures can be dangerous for the electric grid and can cause power outages. To make sure that people continue to have access to power when it’s hot, Menlo Park, California has built a resilience hub with solar panels and battery storage that is a community center open to everyone, which may be especially helpful on the hottest days.
Engaging the Community
Residents and business representatives were engaged throughout this project to share their feedback and thoughts regarding extreme heat events. Team members spoke with more than one hundred residents at various events within and near the project area, and solicited feedback through a community survey. Focus groups were conducted with large property owners along the corridor and local government staff of neighboring and regional jurisdictions.
Residents shared that their primary cooling strategy was to seek air conditioned spaces. Many expressed difficulty paying high summer energy costs, but most were willing to give up other expenses in favor of cooling. Residents shared that they were not personally concerned about heat, though they did have worries about family members, friends, and neighbors who may be more vulnerable to the effects of heat. Other cooling strategies included seeking shade, swimming, hydration, and wearing clothing that blocked the sun.
In consideration of outdoor spaces, most residents expressed preference for tree-lined streets and green infrastructure, though there were some concerns around costs and maintenance. There was strong support for a community cooling center, hydration stations, more shade, and additional public seating options.
Large property owners were generally interested in learning more about green infrastructure practices. There are several barriers to incorporating cooling strategies on these properties, including a disconnect between property owners and tenants, contracted landscaping services, and understanding the cost effectiveness of such strategies. New developments, such as 325 Blake Road, are more easily able to incorporate these strategies into the designs as compared to existing buildings and their surrounding parking areas.
There is interest in collaboration among adjacent and regional local governments to share best practices that address the urban heat island effect more broadly. Resources are available through the Metropolitan Council and the overlapping watershed districts to implement green infrastructure strategies and reduce urban heat island effect in the region.
Engagement events at National Night Out (left image), community resiliency event (middle image), and the farmer's market (right image).
Strategies to Beat the Heat
The following summarizes recommendations based on input from stakeholders, best practices from other cities, and the existing opportunities based on Hopkins' current programs, policies, and regulatory processes. The goal of these recommendations is to reduce the urban heat island effect along this corridor and strengthen the resilience of residents and businesses who will be disproportionately impacted by extreme heat events.
Increase Natural & Green Spaces
Reducing the urban heat island effect can be addressed through natural strategies. These strategies generally involve increasing the amount of and access to nature, like trees and native plants. Increasing the tree canopy coverage and planting more vegetation provides shade and evapotranspiration — the process of plants absorbing and releasing water.
We can reduce surfaces that cannot absorb water, like concrete, and replace them with surfaces that absorb water to keep our neighborhoods cooler. We can also improve bodies of water, like Minnehaha Creek, to ensure they are safe to wade or swim in, allowing people to cool off.
Construct Buildings & Infrastructure in Consideration of Heat
Urban areas have generally been developed without consideration of extreme heat. Changing construction materials can reduce the built environment’s contribution to urban heat island effect.
Pavement: Instead of using traditional dark concrete and asphalt that absorb heat, streets, parking lots, and sidewalks can use cool pavements that are lighter and reflect heat. Underutilized pavement can be replaced with vegetation.
Rooftops: Green roofs convert traditional asphalt roofs to vegetation, which helps keep the roof cooler and provides storm water benefits. Cool roofs use reflective surfaces to reduce the amount of heat that is absorbed.
Building Efficiency: Efficient buildings have quality insulation and efficient mechanical systems, helping to keep indoor spaces cool and costs low.
Shading: Beyond changing building practices and materials, adding awnings and other structures that can provide shade (like bus shelters) can help people who are outside avoid the direct sunlight on hot days.
Improve Social Cohesion
Social cohesion is built on relationships within a community. This can be in a neighborhood, a block, or an apartment complex. Relationships between neighbors, the business community, and city government helps to build strong ties that can keep people safe in times of an emergency, like during an extreme heat wave.
Residents: Knowing the people who live near you has many benefits. During a heat wave, neighbors will know who might need a welfare check or a cool place to stay.
Businesses: Local businesses in communities where there is trust and relationships may open their doors to help keep neighbors cool or provide some of the essentials needed to make it through a heat wave.
City Government: Staff working for city government can build trust among those who are most vulnerable to extreme heat waves. They can provide resources in multiple languages, conduct welfare checks, and make sure everyone has access to cooled spaces. Public cooling spaces might include indoor options like recreation centers or libraries, as well as outdoor spaces like splash pads or wading pools in public parks.
Ensure Access to Reliable & Clean Back-Up Power
Air conditioning is one of the most important tools we have to stay cool during heat waves. Heat waves increase the amount of air conditioning that is used and can strain the electric grid. In times of extreme heat, a power outage can have serious consequences for people’s health.
Back-up power has traditionally come from diesel generators. Advancements in technology have made solar and batteries viable options for clean and long-lasting alternatives.
Micro-grids are systems that provide back-up power to a building that can be isolated from the grid during times of power outages. These can be included at community centers or other public spaces to provide refuge during a power outage.
