Boston residents are facing the third heat emergency of this summer as the city copes with soaring temperatures and a heat index nearing 96 degrees Monday through Wednesday.
“When a heat emergency is issued, that means that the temperature has reached 95 degrees or above for two days or longer,” said Zoe Davis, senior climate resilience project manager with Boston’s Office of Climate Resilience. A heat advisory, which is less serious than a heat emergency, is triggered when the temperature reaches 90 degrees or higher for three days. Both temperature thresholds include an evening temperature of 75 degrees.
In addition to this year’s three heat emergencies, the Boston Office of Emergency Management reports that there has been one heat advisory. Last year, Boston had two heat advisories and two heat emergencies.
The OEM developed these current thresholds in 2018 in partnership with the Boston Public Health Commission. And over the past few years, the city’s heat emergency and advisories have extended both earlier and later in the season. In 2021, there was a heat emergency on June 5. In 2023, there was a heat emergency on Sept. 7.
Davis says they’re forecasting that summer will last even longer in the coming decades; in the next 50 years, she expects around 130 days will have temperatures over 80 degrees.
“That amount of days extends beyond what we understand summer to be, which sort of puts into perspective that our climate is changing and will change,” Davis said.
Some of this can be attributed to rising temperatures due to climate change.
According to the city’s office of climate resilience, Massachusetts has seen its average temperature increase almost 3.5 degrees Fahrenheit since 1900. And over the last decade, the number of hot days and nights have increased more than any decade in the previous 50 years.
“We know that heat is increasing worldwide. We know that the Northeast U.S. is warming faster than other parts of the U.S.,” said Patricia Fabian, associate professor of environmental health at Boston University.
Fabian said it will be normal to see an increase in the number of heat advisories as well.
“Climate is variable, so it doesn’t mean that every year we’ll have more, but on average, heat advisories are going to increase,” Fabian said.
Davis said policy changes happen over long periods of time.
The city has a heat resilience plan; along with setting the temperature thresholds for heat advisories and emergencies, it provides a citywide framework to prepare Boston for hotter summers, with a focus on Boston’s environmental justice neighborhoods.
“I see the development of the heat plan as one of these changes where we were taking the directive of ‘climate ready,’ which focuses on climate preparedness broadly for coastal resilience, stormwater resilience and heat resilience,” Davis said.
During heat emergencies, Boston Emergency Medical Services experiences a 10 to 15% increase in 911 calls. Davis said the declaration triggers several events to help residents stay safe and cool, including the opening of cooling centers, water spray pads and misting programs. During the heat emergency, all Boston Centers for Youth and Family Cooling Centers will be open during normal operating hours. Residents are urged to stay well-hydrated, seek out air-conditioned environments and check on elderly residents or neighbors who may need assistance.
Produced with assistance from the Public Media Journalists Association Editor Corps funded by the Corporation for Public Broadcasting, a private corporation funded by the American people.
