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If it feels this summer has required more time hiding in the air conditioning than enjoying the great outdoors lately, the data officially backs that up. As of Tuesday, Boston is stepping into its second official heat wave of the summer.

Not only is this the hottest meteorological summer (June through August) on record so far, but Tuesday’s heat will officially tip the scales of our seasonal averages. In a typical year, Boston averages about 12 days at or above 90 degrees. The city has already hit that mark — meaning every 90-degree day from here on out pushes Boston into an above-average year.

A three-day sizzler

The heat risk forecasted for Tuesday, July 14, 2026. (Danielle Noyes/1DegreeOutside)

By definition, a heat wave in New England requires three consecutive days of 90-degree temperatures or higher. Boston is locked in to hit that criteria over the next three days, but thankfully, the humidity profile is going to shift a bit.

• Tuesday (the peak): Tuesday is the most intense day of this stretch. Expect a blistering high of 97 degrees in Boston. While it’s unlikely temperatures will break the city’s daily record of 100°F (set back in 1995), several interior New England cities and towns are on track to exceed their local daily records. Factor in the humidity — with dewpoints in the muggy 60s — and the heat index will hover right around or just over 100 degrees.
• Wednesday: High of 92.
• Thursday: High of 91.

While Wednesday and Thursday are still hot enough to keep the heat wave alive, the humidity will drop significantly. Without that heavy, super-sticky air in place, the heat will feel slightly more manageable than Tuesday.

Air quality alert

With “Major to Extreme” heat risks on the table, Heat Advisories are firmly in effect. This kind of heat elevates the risk of heat-related illnesses, especially for vulnerable populations who may not have access to reliable cooling or hydration.

Additionally, Tuesday is an Air Quality Alert Day. High temperatures and bright sunshine are driving up ground-level ozone concentrations. When ozone reaches these levels, the air can become unhealthy for sensitive groups, including older adults, active children, and anyone with respiratory conditions like asthma or heart disease. It is highly recommended that anyone who falls into these categories limit prolonged outdoor activities.

Severe weather threat to the north

While southern New England bakes, a highly active setup is stirring to the north. A strong cold front is diving down, set to trigger a round of severe thunderstorms across northern New England Tuesday evening and overnight. These storms will be capable of producing damaging wind gusts, large hail and even a few isolated tornadoes.

The threat of severe weather forecasted for Tuesday, July 14, 2026. (Danielle Noyes/1DegreeOutside)

The local impact: That cold front will slowly slide south overnight. While the severe storms to the north will weaken as they move into Massachusetts, stray rumble of thunder could clip the northeastern part of the state during the pre-dawn hours on Wednesday morning.

Relief is on the horizon

The light at the end of the tunnel arrives just in time for the weekend:

• Friday: Highs drop back into the comfortable mid-80s with a fresh breeze.
• The weekend kicks off even cooler, with temperatures dropping into the 70s on Saturday. However, it comes with a tradeoff: there will be an unsettled start to the weekend with areas of rain and embedded thunder around.

Stay cool, stay hydrated, and keep an eye on the radar! You can track the current heat index and pinpoint your exact location for weather anytime on the free 1DegreeOutside app!