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'Heat islands' in Boston can be 20 degrees warmer than surrounding areas

BOSTON — There’s no question the past few weeks have been hot in the city, but some neighborhoods can by significantly warmer than others because of “heat islands.”

These areas can have temperatures 20 to 50 degrees higher than the surrounding area, and it’s all because of the concrete and pavement.

"The heat from the surface is just unbearable some days,” one Dorchester resident said.

One stretch of Columbia Road in Dorchester was 81.7 degrees in the shade, but much, much hotter where the sun was beating down.

“Wow, 103.1, that is a 20-degree difference. I didn't realize it was that much hotter,” Dorchester resident Tracy Brooks said.

The city calls them “heat islands.” They're typically in dense urban neighborhoods where there is a lot of concrete and pavement.

"It catches the heat and absorbs it,” Boston Chief of Environment, Energy & Open Space Austin Blackmon said.

The hottest islands are in the Back Bay, Roxbury, Mattapan and parts of Allston.

"Even in the nighttime when it gets cooler that heat starts coming off the buildings and keeps the city much warmer than they would otherwise would be,” Blackmon said.

The excess heat puts a burden on the power grid to cool buildings down and on people with health issues like asthma and diabetes.

But the City of Boston is working to address the problem. One solution has been to plant 1,200 new trees and provide $100,000 to care for the older trees.

"Those trees that have been there for 20, 30, 40 Years, what they add to the canopy is way more than what a new tree will be able to do in next 5 to 10 years,” Blackmon said.

The city is also pushing for more landscaping with new road projects, and has left spacing in the new brickwork at City Hall Plaza to help allow rain water to go into the ground, rather than into drainage basins.

Brooks said she supports anything to cool down these city streets, especially on days like this.

“Yes, the trees will help big time. Let's bring the trees back to the community,” she said.

The city is also pushing greener designs to ongoing projects.