Jun 20, 2023 - Climate

Boston's hot summers are here to stay

Data: Climate Central; Chart: Tory Lysik/Axios Visuals
Data: Climate Central; Chart: Tory Lysik/Axios Visuals

It’s not just you. Boston’s summers are getting hotter.

Driving the news: The city’s average summer temperatures increased by 2.4°F between 1970 and 2022, per a new analysis by climate research group Climate Central.

  • Average temperatures were 74.1°F in 2022, compared to 71.7°F in 1970.

Why it matters: Extreme heat is a serious health risk, leading to both immediate acute effects (such as exhaustion and heat stroke) as well as longer-term complications due to reduced air quality.

  • A particularly deadly "heat dome" phenomenon was linked to dozens of deaths across the Pacific Northwest and beyond back in 2021, lending fresh urgency to the problem of rising city temperatures.

Zoom in: Boston launched a task force last year to oversee heat mitigation and climate resiliency strategies.

  • The city also launched a grant program to help property owners swap out dark roofs that attract more sunlight with lighter, “cooler” roofs. It also gave out 30 pop-up cooling kits for community groups hosting public events.

The big picture: Between 1970 and 2022, summer temperatures rose across nearly 230 locations — 95% of the locations the group analyzed. The average increase was 2.4°F.

  • Average temperature increases were highest in Reno, Nevada (+11.1°F); Boise, Idaho (+5.8°F); Las Vegas (+5.8°F); Salt Lake City (+5.5°F); and El Paso, Texas (+5.3°F).
  • Last year was the third-warmest summer between 1970 and 2022 for Boston.

The bottom line: "As carbon pollution traps more heat in Earth's atmosphere, the summer season is warming, summer temperatures are arriving earlier in the year, and risky heat extremes are becoming more frequent," per Climate Central.


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