The July 2026 East Coast Heat Wave Broke Records From DC to Boston — Here's Every One
A heat dome sat on the I-95 corridor over the July 4th weekend. We pulled the daily highs for nine cities from 56 years of NOAA data. Every one of them set or tied a heat record.
The July 2–4, 2026 heat wave broke or tied a daily high-temperature record in every one of the nine East Coast cities we analyzed. Atlantic City, NJ hit 105.9°F on July 4 — the hottest day in its 56-year record. Newark reached 105°F, Washington DC and Philadelphia both cleared 102°F, and New York City's Central Park touched 100°F for the first time since 2012. Across the three days, these stations set 20 new daily records outright, with several more ties.
We measured it the same way we measure every heat event: by pulling each city's daily high from its primary long-record station in our NOAA records database and stacking July 2026 against every prior year on the same calendar day. This was the exclamation point on an already-hot summer — the same heat dome that made June 2026 a top-5 hottest June for Boston, Philadelphia and DC didn't break at the end of the month. It intensified into July.
A dome of high pressure that wouldn't move
Heat waves like this one are a plumbing problem in the atmosphere. A strong ridge of high pressure — the “heat dome” you keep hearing about — built over the eastern third of the country in the last days of June and simply refused to budge. Sinking air under a ridge warms as it compresses, dries out clouds, and lets the sun cook the surface day after day. By July 2, the National Weather Service had more than 200 million Americans under some form of heat alert, with heat-index values flirting with 110–115°F from Texas to the coast.
What made this event stand out wasn't a single freak number — it was how many places set records at the same time. When one city breaks a daily record, that's weather. When Boston, New York, Philadelphia, Baltimore, Washington, Newark, Atlantic City, Richmond and Raleigh all break or tie one inside 72 hours, the ridge was doing the same thing to the entire Eastern Seaboard. And it landed on the worst possible weekend for it: the Fourth of July, when tens of millions of people were outdoors.
Nine Cities, Three Days: The Daily Highs
Daily high temperature (°F) at each city's primary NOAA station for July 2–4, 2026.R = broke the daily record, T = tied it. Records compared against 1970–2025.
| City | Station | Jul 2 | Jul 3 | Jul 4 |
|---|---|---|---|---|
| Atlantic City, NJ | Intl Airport | 102.9°R | 105°R | 105.9°R |
| Newark, NJ | Liberty Intl | 105°R | 102.9°R | 98.9° |
| Washington, DC | Reagan National | 102°R | 102°R | 102.9°R |
| Philadelphia, PA | Intl Airport | 102.9°R | 102°R | 100.9°R |
| Raleigh, NC | RDU Airport | 98°R | 100.9°T | 102.9°R |
| Baltimore, MD | BWI Airport | 100.9°R | 102°R | 102°R |
| Boston, MA | Logan Airport | 100.9°R | 100°R | 93.9° |
| New York, NY | Central Park | 100°R | 98°R | 93.9° |
| Richmond, VA | Intl Airport | 96° | 98.9°T | 100°T |
Source: NOAA NCEI GHCN-Daily via our records database, queried July 8, 2026. Values are the official daily maximum at each station. Our continuous daily record begins in 1970.
The five records that actually matter
A record by one degree is a footnote. A record by seven or nine degrees is a different animal — it means the day wasn't just hot for the date, it was hot for the place, period. These are the ones worth remembering:
- Atlantic City — 105.9°F (July 4). This wasn't just a daily record; it tied the hottest day of any date in Atlantic City's 56-year record. The old July 4 mark was 96.9°F. A shore town known for sea breezes ran nine degrees past it.
- Newark — 105°F (July 2). Seven degrees over the previous July 2 record of 98°F. Newark and Atlantic City were the two hottest spots on the corridor, both in New Jersey.
- Boston — 100.9°F (July 2). Boston reaching 100°F is genuinely rare — the city can go years between triple-digit days — and this beat the old July 2 record by seven full degrees.
- Philadelphia — 102.9°F (July 2). That tied Philadelphia's hottest July day in our entire 1970–2026 record, six degrees above the old date record of 96.9°F.
- New York (Central Park) — 100°F (July 2). The first time the city's benchmark station hit triple digits since July 18, 2012 — nearly 14 years. The previous July 2 record was just 95°F.
Washington DC deserves its own line: it broke the daily record three days running — 102°F, 102°F, then 102.9°F on the Fourth. Baltimore did the same. When a city can't catch a break for 72 straight hours, that's the dome, not the calendar.
A note on “records”
Every number here is the official daily high from that station, pulled straight from NOAA's GHCN-Daily archive. Our continuous, gap-free daily record begins in 1970, so when we say “a record in 56 years” we mean since 1970. The National Weather Service keeps longer books — its official records for Washington, Philadelphia and New York stretch to the 1870s — and by the NWS reckoning, several of the marks that fell over this weekend had stood for a century or more. We flag the difference so the numbers are honest: our data proves these were the hottest such dates in over half a century; the NWS record shows some were the hottest in far longer.
Is this just what summer looks like now?
Honestly? Increasingly, yes — at least the frequency of it. A single heat dome is weather, but the East Coast has been trending hotter for decades, and our own data shows it: many major cities are running their warmest summers on record since 1990. A warmer baseline means the same weather pattern that would have produced a 96°F day in 1985 now produces a 102°F day. You don't need the pattern to be more extreme; you just need to start it from a warmer floor.
This summer has an extra thumb on the scale: a developing El Niño. Our Summer 2026 outlook flagged above-normal heat for most of the country, and El Niño 2026 tends to nudge summer temperatures up across the eastern US even as it suppresses Atlantic hurricanes. For a sense of scale, compare this event to the all-time extremes on our hottest temperatures ever recorded page — the East Coast still doesn't touch Death Valley, but 105°F in Atlantic City is its own kind of remarkable.
Curious what your own city did on any date? Our historical weather lookup pulls the daily high and low for any US location going back decades — type in a date and see how July 2026 stacks up where you live.
Frequently Asked Questions
How hot did it get during the July 2026 East Coast heat wave?▾
The heat peaked July 2—4, 2026. Atlantic City, NJ hit 105.9°F on July 4 — the hottest day in its 56-year NOAA record. Newark reached 105°F, Washington DC and Philadelphia both topped 102°F, Baltimore hit 102°F, and Boston and New York City each reached 100°F or higher. Across the nine I-95 corridor cities we analyzed, every single one set or tied a daily heat record.
Did New York City break a heat record in July 2026?▾
Yes. Central Park reached 100°F on July 2, 2026 — the first time New York City hit triple digits since July 18, 2012, and a new record for the date (the old mark was 95°F). It broke the July 3 record too, hitting 98°F.
What caused the July 2026 heat wave?▾
A strong upper-level ridge — a "heat dome" — parked over the eastern US, trapping hot, sinking air and clear skies over the I-95 corridor for several days. It arrived on the heels of an unusually warm June and a developing El Niño, and at its peak more than 200 million Americans were under heat alerts, per the National Weather Service.
Was this the hottest heat wave on record for the East Coast?▾
For several cities, these were the hottest days in decades. Atlantic City tied the hottest day in our 56-year record, and Philadelphia tied its hottest July day since 1970. Per the National Weather Service, some of the daily records that fell in Washington DC and Philadelphia had stood for a century or more. It was not the highest temperature ever recorded on the East Coast — Newark, for example, has reached nearly 108°F in our record — but the breadth of records broken across so many cities at once was extraordinary.