Community Heat Mapping in Montgomery County
In August 2022, Mongtomery County conducted heat mapping to understand extreme heat in our area and generate collaborative solutions
Kids cool off at one of Montgomery County's many public pools in a heat wave
In August of 2022, Montgomery County conducted a community heat-mapping initiative that brought together local organizations and volunteers to produce heat maps and generate creative and collaborative solutions for extreme heat in our area. Montgomery County was one of 16 jurisdictions globally that collaborated with the National Oceanic and Atmospheric Administration (NOAA) and community scientists to map heat inequities.
Extreme heat kills more Americans than any other weather event, but not everyone’s risk is the same. Low-income communities and communities of color are disproportionately impacted by extreme heat. These local maps will help us identify where we can take action to protect vulnerable neighborhoods both now and in the future.
This story map provides background on extreme heat in Montgomery County, an overview of the community heat mapping, and shares some of the preliminary results from the data collection.
Heat in Montgomery County
As Montgomery County faces the impacts of climate change, average annual temperatures are projected to increase significantly, and the greatest changes will occur in the summer and fall. Heat waves are among the most dangerous natural hazards in the County. Their intensity and frequency are increasing due to climate change, as indicated in Montgomery County’s Climate Action Plan.
By the year 2100, Montgomery County residents could experience almost two full months each year with temperatures reaching above 95°F. Even by 2035, we can expect to experience an average of 12 days each year with temperatures reaching above 95°F, three times more than the County is experiencing today.
Extreme heat can cause dangerous health outcomes for those exposed, especially for seniors, infants, outdoor workers, people with preexisting health conditions, and people without access to air conditioning. As the lead cause of climate-related deaths in the United States, heat is dangerous weather that must be handled with care.
Heat exhaustion can directly lead to dehydration, heatstroke, and even heart issues. In areas where extreme heat is more common, long-term exposure can worsen chronic cardiovascular and respiratory illnesses. Extreme heat can also impact psychological well-being. Climate scientists find links between long-term heat exposure and mental health outcomes, such as aggression and chronic fatigue. Heat can also damage built infrastructure, especially in urban environments.
“It was while I was playing a sport, and it was around, like, April or March; it was hotter than usual. And I just remembered, I was standing, and then I was feeling more tired and fatigued. Everything felt slow, and I saw some black dots, and my vision started to get darker. At one point, I was kind of falling forward, but I regained my balance once I was aware. Everything went back to normal, but I was still tired.” -Quote from community member on heat exhaustion
Although our climate is warming universally, individuals in Montgomery County are not impacted by extreme heat equitably.
Projected increases in average temperatures and heat waves can be exacerbated by a phenomenon commonly referred to as the urban heat island (UHI) effect. The urban heat island effect occurs in densely populated areas where sunlight is absorbed and retained by paved surfaces and roofs. Trees and vegetation can keep temperatures cool by deflecting the sun, providing shade, and releasing moisture into the atmosphere.
Urban areas tend to have less vegetation and greater concentrations of impervious surfaces (surfaces that cannot drain water like sidewalks, roads, and, roofs), creating “islands” with significantly higher temperatures compared to surrounding suburban or rural areas. Average temperatures in urban areas can rise 1–7°F higher than temperatures in outlying areas.
To better understand where UHIs are in the County and adapt to worsening heat, Montgomery County worked alongside NOAA and CAPA Strategies to map temperature and heat index levels across the County.
"Our Climate Action Plan is clear - extreme heat is among the most dangerous natural hazards in the County. Right now in Montgomery County, we are experiencing more intense and more frequent heat waves due to climate change. Tracking the Urban Heat Islands will help us identify the areas across the County that need immediate attention and will help us as we plan development in the future. I applaud the federal government for this effort and am proud Montgomery County is taking a key role in collecting this important data that will help the County and the nation as we seek solutions to the heat-related issues caused by climate change.” - County Executive Marc Elrich
Campaign Day
County Executive Marc Elrich speaking to community volunteers and media on Campaign Day
On August 7, 2022, community volunteers across the County, called street scientists, mapped urban heat in 200sq miles of Montgomery County, encompassing densely populated areas like Gaithersburg, Germantown, Rockville, Silver Spring, Bethesda, Fairland, and Olney. This community heat mapping would not be possible without the support of the community. After announcing the heat mapping campaign, almost 600 prospective volunteers expressed interest in the project, indicating just how important this initiative is for whole the County.
Some volunteers acted as “Street Scientists” and collected heat data along specific routes. Other signed up as neighborhood organizers to gather stories on heat in their neighborhood and to share information on heat health in Montgomery County. Some quotes from the stories collected by neighborhood organizers can be found throughout this story map.
“I noticed that when I got off work at seven o’clock in the morning, it was already at 87 degrees. The heat was everywhere in the morning because I gave my son a ride to work; it was from Fairland, Maryland, to the DC area, and then it got hotter by the time I got home at 9 am. As you know, this is unusual.” -Quote from Community Member collected by Neighborhood Organizer
Afternoon Traverse Data from the routes and areas where the street scientists drove
Over one hundred Street Scientist volunteers traversed 19 different routes around the County at 6 am, 3 pm, and 7 pm to track the real-feel heat over the course of an extremely hot day in the summer. Street Scientists drove along predetermined routes with a simple data-collection device attached to the vehicle to measure surrounding temperature and humidity.
Laura Sivels from the Montgomery County Department of Environmental Protection and the project coordinator for the Heat Mapping Campaign explained how the devices work.
The heat hubs had handheld FLIR cameras on site for visitors to see how various surfaces impact heat
In addition to conducting the heat mapping, there were four heat hubs throughout the county to share information about extreme heat. Many partners and community members participated at the heat hubs during the campaign day including from One Montgomery Green, NOAA, and even The White House Office of Science and Technology Policy. Within the County, the heat hubs included visits from the County Executive and representatives from the County Department of Environmental Protection, Office of Emergency Management and Homeland Security (OEMHS), Montgomery Parks, and Montgomery Planning. In addition to the volunteers and partners, there was an outpouring of local, regional, and even international media on site to document the data collection process.
Two of Montgomery County's Heat Hub Stations on Campaign Day, and Street Scientists
“Scientific evidence drives action . . . President Biden and Congress have made funds available for tree planting, roof gardens, resurfaced outdoor play and sports facilities, and better insulation to keep the cool inside our buildings. There’s nothing more compelling to spur action than local communities empowered with the facts about where the hottest spots are, and how to tackle these inequities in heat exposure." - Dr. Gretchen Goldman, Assistant Director for Environmental Science, Engineering, Policy and Justice for the White House Office of Science and Technology Policy
Results
Swipe right to see AM temperatures, swipe left to see PM temperatures
Swipe right to see Tree Canopy, swipe left to see PM temperatures
Tree canopy plays a major role in the dissolution or creation of Urban Heat Islands. Trees can help with heat by providing shade and releasing moisture into the atmosphere. Increased tree planting and green space development are major drivers of heat resilience.
Swipe right to see PM temperatures, swipe left to see Land Cover
The County uses precise land cover datasets provided by the Environmental Protection Agency to compound our understanding of Heat Islands, and why they exist where they do. Above, with the ability to zoom in and view a legend on the bottom left, look to see where some denser heat islands correlate to dense urban areas, or impervious surfaces. Also, see where heat dissipates upon water or tree canopy.
Urban Heat Rasters and Equity Emphasis Areas (2022)
“The hottest spots are going to tend to be low-income communities and communities of color that are most impacted by this…redlining, which saw banks limit housing loans to residents of certain poor, Black neighborhoods marked with a red line on maps, reinforced segregation—with hotter communities today as a result. We were able to see the impact of that discriminatory policy even decades and decades later,” - Dr. Gretchen Goldman
Response and Solutions
After completing the urban heat mapping campaign, we have a better understanding of where the hottest areas are and who has the highest heat risk. So, the question is, how will we use the data we collected and where do we go from here? The County has begun working on several immediate responses to increase our heat resilience and is collaborating with other organizations to work on longer-term solutions. In the meantime, there are also some steps you can take to be prepared for extreme heat.
Emergency Preparedness
To learn more about emergency preparedness, visit the Office of Emergency Management and Homeland Security (OEMHS) webpage. The site details the four steps to emergency preparedness 1) Stay Informed, 2) Make a Plan, 3) Make a Kit, and 4) Get Involved. OEMHS has many resources to create a plan and kit for your family, friends, and neighbors for emergency readiness, and these plans don’t have to be complicated or expensive. Getting involved can encompass obtaining a speaker for your neighborhood, volunteering at an organization, training opportunities, or even talking about extreme heat with family, friends, and neighbors. Follow this link to learn more.
Extreme Heat Health
Another informative website is heat.gov, the National Integrated Heat Health Information System (NIHHIS) website, which is a source of information regarding heat and health for the nation. NIHHIS has many educational tabs on its website, including planning and preparing, news and events, learning, urban heat islands mapping, tools and information, and at-risk groups.
To cool down, you can access your County facilities if you are outside during extreme heat and need respite from the heat. These include libraries, swimming pools, recreation and senior centers, and regional services centers open during regular business hours.
During the summer, for updates on advisories and emergencies, tips on keeping people and pets safe, and/or should a decision be made that a cooling center is needed, information will be posted on the Montgomery County Home page under “News Releases,” or you can call 311 which is the non-emergency government information and services.
Alert Montgomery
Stay informed through Alert Montgomery, an emergency notification system that will alert you of weather, traffic, infrastructure issues, and government and school status. The system delivers accurate and immediate emergency announcements from Montgomery County to your cell, work, or home phones via text, email, or voice message. This way, you will be prepared for any extreme weather event. Sign up here .
Tree Montgomery
Trees are vital for our health and the health of the environment around us. Trees and vegetation can help lessen the impacts of extreme heat by providing shade and releasing moisture into the atmosphere. Mature trees absorb more carbon and water than recently planted trees, so taking care of developed trees in your neighborhood is important. You can also increase heat resilience by planting trees. Tree Montgomery focuses on planting shade trees to build the County’s tree canopy. Just sign up here and a staff member will contact you to schedule a tour of your property. If your property is a fit, they will order and schedule planting, and explain how to care for your tree.
Next Steps
Montgomery County's Climate Team is working to share the results with different agencies and partners in community planning like Montgomery Planning’s Master Plans, Office of Emergency Management’s Hazard Mitigation Plan, our nature-based solutions planners, etc., and to develop plans and strategies to mitigate, adapt, and build resiliency to the extreme heat in Montgomery County.
County officials will use this information to shape programs when working with particularly vulnerable groups like seniors, community members with a disability, those experiencing homelessness, without air conditioning, relying on public transportation, or working outside.
“I think when it is hot out there, we may need cooling centers. Some cooling centers for people, like the homeless or those who are out. They might want to go there, cool off, and rest without going into a store or somewhere like that.” -Quote from communtity member collected by Neighborhood Organizer
Thriving Earth Exchange
The Thriving Earth Exchange supports community science by helping communities find resources, project managers, and experts to address their pressing concerns. Together, they help communities be more empowered, resilient, and responsive. They will assist Montgomery County in building a tool to understand urban heat, the locations of all heat islands, how heat disproportionately impacts communities, and how heat relates to the tree canopy and impervious surfaces.
These results will help us to prioritize tree planting and identify locations for future cooling centers (such as outdoor spray areas, public water fountains, shaded zones, public buildings, etc.). The results will also include developing stronger individual and group tree protection measures on private and public lands and implementing other heat-management strategies and resources ( Thriving Earth Exchange, 2022 ).
Nature-Based Climate Initiatives
The County is also receiving technical assistance from the Urban Sustainability Directors Network’s Nature-Based Climate Initiatives (formerly the Urban Drawdown Initiative) and Nature-Based Climate Solutions to inventory the current status of Montgomery County programs, policies, and initiatives that provide nature-based carbon sequestration solutions and explore potential future programs. This initiative and the Thriving Earth Exchange program should merge into one essential program for Montgomery County to meet the Climate Action Plan’s goals.
Nature-based solutions are sustainable planning, design, environmental management, and engineering practices interlacing with natural features or processes in the built environment to promote adaptation and resilience (FEMA, 2022).
“It’s going to take all of us to be a climate-ready nation. And if we work together, we can do it.” -Ken Graham, National Weather Service
Media
“I signed up right away. I thought this is exactly what the County should be doing, and we should be learning about what’s going on with climate change and the impacts.” - Criminology Professor Maria Velez
