Boston is in for a dangerously hot Thursday, with the high near 100°F and a heat index climbing as high as 107 degrees — so if you’ve got errands or outdoor plans, get them done early and plan to be somewhere air-conditioned by early afternoon.
Today’s Setup
The National Weather Service says today and Friday mark the peak of a prolonged, dangerous heatwave gripping Greater Boston, with near-record highs of 97 to 103°F and heat indices reaching 105 to 115 degrees this afternoon. Skies stay mostly sunny with a west wind around 9 to 14 mph, and forecasters note isolated showers and thunderstorms could pop up between 1 and 2 PM ET — there’s only a 20% chance, but if a storm does fire, it could turn strong given how much energy is in the atmosphere. Overnight brings little relief, with a low near 79°F and heat index values still near 105.
Best Window To Be Outside
Morning, before 10 AM ET, is your best bet for a walk along the Charles River Esplanade or a loop around Boston Common. By midday, pavement in spots like the Seaport and Fenway will feel brutal, and the NWS is flagging this as genuinely dangerous heat, not just uncomfortable — limit strenuous activity outdoors during peak afternoon hours.
Heat, Storm, And Wind Risk
This isn’t a garden-variety hot day. The Area Forecast Discussion calls it a “dangerous prolonged heatwave” continuing through Saturday’s Fourth of July, with thunderstorm and severe weather chances increasing late Friday into Saturday ahead of an approaching cold front. Any storm today has a low but real chance of turning severe given the atmospheric instability in place.
What To Wear Or Bring
A lightweight linen shirt breathes far better than cotton in this humidity, and you’ll want an insulated water jug 1 gallon on hand to stay ahead of dehydration — heat index over 100 sneaks up fast. If you’re headed to the river or a pool this weekend, pack a women’s swimsuit or quick dry swim trunks and men’s sport sandals for wet pavement and boat docks.
Heading to Leader Bank Pavilion tonight for the Kes - Roots, Rock, Soca Tour? It’s an open-air venue, so hydrate before you go and check tickets on SeatGeek or Find tickets on StubHub before showtime. James Taylor plays outdoor Tanglewood Friday night, right as heat indices stay in the 100-110 range — same advice applies.
Helpful Links
With storms possible late Friday into Saturday, it’s worth having backup power on hand — the DARAN 288Wh Power Station is discounted for Prime members right now and works well for keeping fans or phones running through a brief outage.
Tonight’s Dinner
With highs like this, skip the stove. A cold Thai noodle salad, a build-your-own wrap bar, or smoothie bowls are the move tonight — a high-powered blender makes quick work of smoothies, and an insulated tumbler 30oz keeps drinks cold for hours outside. Need ingredients? You can order groceries on Amazon and have everything for tonight’s dinner delivered to your door.
Next Few Days
Friday repeats today’s extreme heat with a high near 101°F and heat index up to 106, plus a slightly better (31%) chance of scattered storms Friday night. Saturday, July 4th, stays hot in the 90s with heat indices of 95-100+, still risky for outdoor holiday plans, but the NWS expects cooler, more seasonable air to finally arrive during the first half of next week.
