B-COOL pilot project data shows impact of heat across several Boston neighborhoods
January 22, 2025
Boston – A Better City, in partnership with the Boston Foundation, Boston University’s School of Public Health, and the City of Boston’s Office of Climate Resilience, celebrates the completion and preliminary results of a heat sensor pilot program to address the data gaps in measuring temperature data across Boston’s hotspot neighborhoods, which can be 10-15 degrees warmer than surrounding neighborhoods. In the pilot, known as B-COOL, a total of 15 sensors were installed at 12 A Better City member and partner properties, as well as on three City-owned trees, across neighborhoods identified in Boston’s 2022 Heat Plan. This pilot program aims to provide neighborhood-specific temperature data to augment National Weather Service station data and to better inform city officials in declaring heat emergencies and advisories and in supporting vulnerable Bostonians. The results of this pilot could help inform the city, local institutions, and community-based partners on how to distribute available resources to heat-vulnerable residents, workers, and neighborhoods on hot days. Data may more broadly guide future policy initiatives for community heat resilience undertaken by both the public and private sectors.
Currently, there is only one National Weather Service temperature sensor in the City of Boston, located at Logan Airport, which determines the official temperature for the entire city. To reach a declared heat emergency in Boston, temperature predictions based on the National Weather Service station at Logan must be 95 degrees Fahrenheit or higher for two consecutive days when nighttime temperatures do not fall below 75 degrees. B-COOL measurements confirmed that temperatures in some hotspot neighborhoods are reaching this threshold much sooner and more frequently.
Through this pilot program, which ran from June-September 2024, sensors were placed in hotspot neighborhoods as defined and identified in the City of Boston 2022 Heat Plan, and in environmental justice communities, including in the neighborhoods of Chinatown, Dorchester, East Boston, Mattapan, and Roxbury, as well as in Allston-Brighton and Jamaica Plain. This pilot builds upon existing research done by the City of Boston, the C-HEAT Project in Chelsea & East Boston, Wicked Hot Boston, Wicked Hot Mystic, and others.
Key Takeaways
- On hot days, temperatures in local heat island neighborhoods can be significantly higher than the National Weather Service (NWS) Station
- On some hot days, heat advisory and emergency thresholds are met in hotspot neighborhoods but not at the NWS station, with heat advisories and emergencies starting before and extending past NWS-based declarations for Boston.
- Within-neighborhood temperatures can vary significantly, with heat advisory/emergency thresholds being met in some local areas and not others, suggesting that some sub-neighborhoods of hotspot communities are at even higher risk from heat exposure.
- Where sensors are located to measure temperature in cities is important for planning and emergency response as well as meeting equity goals.
- Temperature sensors can be a powerful engagement tool for framing emergency preparedness and response in cities, as well as for local businesses, community-based organizations, and institutions to learn more about how to protect the residents, workers, and community members that they serve during heat events.
B-COOL sensor data affirms what was clarified in Boston’s Heat Plan: extreme heat is a racial justice and climate justice issue, with our environmental justice neighborhoods and communities of color experiencing higher heat and longer duration of extreme heat during heat events in Boston than surrounding neighborhoods, and when compared to the NWS data. Solutions for heat resilience must embed equity and community-based action to support neighborhood heat resilience and adaptability, and neighborhood-specific temperature data could be a helpful tool to inform response and preparedness.
During one declared heat advisory event in summer 2024, there were several sensors that recorded hotter temperatures, breaking the heat emergency threshold, whereas one of our cooler sensor locations never reached heat advisory or emergency conditions for that timeframe. This indicates significant differences in where heat advisory or emergency conditions are being felt across the city (differences both within and across neighborhoods), and for how long neighborhoods are exposed to high heat, compared to the alerts based on temperature data collected from the National Weather Service station at Logan Airport.
The pilot project team is grateful for the partnership of A Better City member and partner organizations: Arnold Arboretum (Harvard University), Bay Cove Human Services, Boston Children’s Hospital, Boston Chinatown Neighborhood Center, Boston Green Academy, Boston Medical Center, Charles River Community Health, City of Boston’s Urban Forestry Division, Franklin Park Zoo, Greenway Conservancy, Mattapan Food and Fitness Coalition, Museum of Science, and UMass Boston. A Better City members were interested in participating in the heat sensor pilot to better understand how to protect their workers, patients, students, vulnerable communities, businesses, and critical infrastructure from the increasing impacts of extreme heat.
“Extreme heat is already impacting our vulnerable communities and infrastructure alike, so it is critical to measure real impacts and develop actionable resilience solutions with a sense of urgency,” said Kate Dineen, President and CEO of A Better City. “This collaborative partnership confirmed our hypothesis that there are instances of unrecognized heat emergency conditions in hotspot communities across the city. As this project suggests, neighborhood-specific and community-informed temperature data should be leveraged as a powerful tool for more effective heat emergency response, preparedness, and equitable resource allocation over time.
Additional Statements from Pilot Project Team Partners
Isabella Gambill, Assistant Director of Climate Energy & Resilience, A Better City
“Temperature sensors are poised to be a powerful community engagement tool in helping local businesses, non-profit organizations, healthcare providers, schools, and community-based organizations better understand how heat might impact the communities that they serve. We are grateful to our countless community partners who made this project possible, and who demonstrated the power to be found in neighborhood-specific and community-driven data, for community-driven solutions.”
Dr. M. Patricia Fabián, Associate Professor of Environmental Health and Associate Director of the Institute of Global Sustainability, Boston University School of Public Health
“Cross-sector collaborations like this Boston extreme heat project are the future for advancing climate resilience efforts in cities, and we hope to generate actionable information for different stakeholders, including the city, businesses, community partners and researchers. As a public health researcher, ultimately my goal is to see improved population health and reduced health inequities through collaborative climate projects like this one.”
Brian Swett, Chief Climate Officer, City of Boston
“Addressing extreme heat is a top priority for Boston to improve our resilience to the impacts of climate change. This heat sensor pilot project is a crucial step towards understanding and mitigating the disparities in heat exposure across our neighborhoods. By filling critical data gaps, we can develop more equitable heat resilience strategies and better protect our residents. I am thankful to our partners including A Better City, Boston University, and The Boston Foundation, as well as Zoë Davis from the City who has been crucial to Boston's work to equitably respond to extreme heat.”
Julia Howard, Senior Program Officer, The Boston Foundation
"The B-COOL data reaffirms that any commitment we make to housing equity needs to include an attention to elements of climate in our neighborhoods," said Julia Howard, Senior Program Officer at the Boston Foundation. "We cannot make progress on climate resilience without addressing the issues this pilot program underscored - that many areas feeling the greatest heat are those that lack the green space and infrastructure to mitigate it."