Boston heat advisory set for July 9–10: what residents should do, cooling resources, and who’s most at risk

The City of Boston has issued a heat advisory for Thursday, July 9 through Friday, July 10, warning residents to take extra precautions during a period when the highest heat indices are expected to reach about 96 to 99 degrees with limited relief evening and overnight.

Mayor Michelle Wu urged residents to use city cooling options, stay hydrated, and check on each other—especially older adults, children, people with medical conditions, outdoor workers, and people experiencing homelessness.

Heat advisory dates and what to expect

The advisory was issued Wednesday, July 8, and is active Thursday, July 9 through Friday, July 10. The City expects the most intense conditions during this stretch, with heat indices around 96°F to 99°F.

During heat waves, Boston Emergency Medical Services typically experiences a 10–15% increase in calls to 9-1-1 for people of all ages.

Who’s most at risk in Boston

The City’s guidance highlights several groups who should plan ahead and be extra cautious:

• Older adults and seniors
• Children
• People with medical conditions
• Outdoor workers and anyone spending long periods outside
• People experiencing homelessness

What residents should do during July 9–10

Boston’s heat-safety tips focus on reducing heat exposure and acting early:

• Stay hydrated: drink plenty of fluids, and avoid alcoholic beverages and liquids high in sugar or caffeine.
• Cool down often: use frequent cool showers, shade, and air conditioning or fans.
• Take shade breaks if you can’t avoid being outside; drink water constantly—even if you are not thirsty.
• Know warning signs: watch for dizziness, nausea, or confusion.
• Protect skin: use sunscreen with SPF 30 or higher and wear protective, loose-fitting clothing and hats.
• Use AC safely: secure window air conditioner units according to the manufacturer’s specifications, and plug fans and air conditioners directly into a wall outlet (never use extension cords or overload power strips).
• Check on neighbors, especially older adults and people with disabilities.
• Keep pets cool and indoors when possible.

If you need help getting to a cooler space, the Age Strong Commission offers discounted taxi vouchers for seniors and people with disabilities. Call 617-635-4366 for more information.

Where to cool off in Boston (July 9 and July 10)

The City points residents to cooling options during the advisory period—generally available during normal/regular operating hours. Because hours can vary by site, the City recommends checking its updated listings.

• Pools and splash pads: splash pads are open at various parks and playgrounds, and several city pools are available. Use the City’s updated pool/splash pad listings for locations and operating hours.
• BCYF community centers: BCYF locations are available during normal business hours on Thursday, July 9 and Friday, July 10.
• Boston Public Library branches: BPL locations are available for relief from the heat during their regular hours on Thursday, July 9 and Friday, July 10.

Heat illness: what it can look like and when to get help

CDC/NIOSH guidance distinguishes between heat stroke (an emergency) and heat exhaustion (which still requires prompt action).

Heat stroke (call 911)

Heat stroke is the most serious heat-related illness. CDC/NIOSH lists symptoms such as confusion or altered mental status, slurred speech, loss of consciousness, seizures, and a very high body temperature. The guidance is to call 911 immediately for emergency care, and move the person to a shaded, cool area while help is on the way.

Heat exhaustion (get medical help fast)

Heat exhaustion can include heavy sweating, cool and clammy skin, dizziness, nausea, and muscle aches. If symptoms persist, the City says to call 9-1-1 immediately—do not delay care. CDC/NIOSH also recommends getting medical evaluation, and calling 911 if medical care isn’t available.

Special guidance for homelessness

The City says to call 911 if you see a person experiencing homelessness who appears immobile or disoriented.

The Boston Public Health Commission uses a citywide emergency shelter network with air conditioning that is open 24 hours a day, seven days a week. When temperatures are 90 degrees or above, an amnesty process applies for nonviolent restrictions. The City also notes its street outreach teams keep operating during the extreme heat window and provide water to people who need it.

How to stay updated

The City directs residents to follow AlertBoston for updates and guidance during extreme weather events. If you rely on public transportation, work outdoors, care for young children, or support someone medically vulnerable, check alerts in advance so you can plan cooling breaks during the hottest hours.

Sources

• City of Boston: heat advisory (July 9–10, 2026) and cooling/safety tips
• CDC/NIOSH: Heat-related illnesses (heat stroke vs heat exhaustion; first aid and 911 guidance)

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