Philadelphia, PA – Overnight lows across the mid-Atlantic failed to cool down Sunday, setting or tying eight new records for warmest minimum temperatures, including 77° in Wilmington and Philadelphia.
According to the National Weather Service in Mount Holly, nine climate stations recorded abnormally high overnight lows on June 23. Wilmington’s low of 77° tied its all-time warmest June low, previously matched four times dating back to 1894. Other record-tying lows included 78° at both Atlantic City Airport and Marina, 76° in Georgetown, 73° in Allentown, and 70° at Mount Pocono.
Philadelphia and Wilmington were among the hardest hit, where the lack of nighttime cooling adds stress to aging infrastructure and raises health concerns—especially for seniors and outdoor workers. With highs nearing triple digits, emergency officials are urging residents to stay hydrated, avoid peak sun hours, and check on vulnerable neighbors.
This unseasonable warmth follows seven daytime records set or tied just 24 hours earlier. All affected stations remain in contention for another round of record overnight warmth tonight, with updated figures expected later this afternoon.
