BETHLEHEM, Pa. — A blistering heat dome that settled over the East Coast this week shattered dozens of temperature records and delivered one of the hottest stretches of weather ever recorded in parts of the Mid-Atlantic and Northeast.
That includes the Lehigh Valley, where overnight lows were the warmest on record for June.
The Northeast Regional Climate Center tracked temperatures that soared into the 90s and 100s, with sweltering overnight lows that stubbornly held in the 70s and 80s.
All told, the historic heat wave broke or tied records at more than two dozen major weather observation sights, the NRCC said.
Heat strained the power grid
The Massachusetts Emergency Management Agency reported more than 13,000 customers without power Tuesday — the same day eight of the region’s 35 major climate sites reported record-setting heat.
The NRCC said Islip, New York; Kennedy Airport, New York; and Providence, Rhode Island, all hit 100 degrees for the first time ever in June.
In total, 20 major sites recorded high temperatures that ranked among the Top 10 hottest Junes on record, with some locations among the hottest ever observed in any month.
Among the most notable extremes:
- Newark, New Jersey hit 100 degrees or higher on three consecutive days, the longest such streak in June.
- Atlantic City, New Jersey and Kennedy Airport each experienced back-to-back 100-degree days — also a first for June.
- Several cities including Bridgeport, Connecticut; Burlington, Vermont; and Islip, New York, notched two days with highs of 95 degrees or higher, breaking their records.
Little relief after sunset
But it wasn’t just the daytime swelter rewriting the record books — nighttime brought little relief.
At 26 of the 35 sites analyzed, overnight lows ranked among the 10 warmest for June.
In New York's Central Park, the mercury failed to drop below 80 degrees for three straight nights — tying the park’s longest such streak for any month since recordkeeping began in 1869.
Chart: High Minimum Temperature Records
| Station | Date | New Record | June Rank |
| Allentown, PA | June 24 | 75 degrees | 1st |
| Bridgeport, CT | June 25 | 76 degrees | 1st |
| Central Park, NY | June 24 and June 25 | 81 degrees | 1st |
| Islip, NY | June 25 | 77 degrees | 1st |
| Kennedy Airport, NY | June 25 | 81 degrees | 1st |
| Newark, NJ | June 25 | 85 degrees | 1st |
| Wilmington, DE | June 25 | 78 degrees | 1st |
Newark also recorded three consecutive nights with lows of 80 degrees or above, a first for the city in June.
Other overnight temperature records included:
- Atlantic City, New Jersey, and Wilmington, Delaware, each logged four nights with lows at or above 75 degrees — the most ever recorded in June.
- Islip, New York, had three such nights, also setting a local record.
- Kennedy Airport and Hartford, Connecticut, joined the list with multiple days above the 75-degree threshold.
In the Lehigh Valley, the National Weather Service said June 24 saw both a record high temperature tied and record warmest low temperature ever for the month.
The high of 98 degrees tied the daily record of 98 set in 1923.
But in addition to the tied record high, a record warmest low temperature of 75 degrees also was set.
It broke the record of 71 degrees set in 2010 and tied the record warmest low temperature for the entire month of June (tying June 29, 1959, and June 29, 1991).
Hottest day in more than a decade
The prolonged stretch of extreme heat not only strained the power grid, it buckled roads across the nation, prompted public health warnings and curtailed outdoor activities.
Numerous deaths from the heat also were reported in Texas, Missouri, Ohio and South Carolina.
Beyond the NRCC, a report from Weather.com meteorologist Jonathan Erdman said June 24 was the hottest day in more than a decade for millions of residents across the Northeast.
Even as the heat finally eased in the Lehigh Valley on Thursday, the Washington Post said parts of 18 states, the Ohio Valley to the Deep South and the Carolinas to the Mid-Atlantic remained under heat alerts.
