Philadelphia, PA – A late-spring heat surge pushed temperatures past 90°F for the first time this year across parts of Pennsylvania, New Jersey, and Delaware on Thursday, June 12—roughly two to three weeks behind the historical average.
According to the National Weather Service in Mount Holly, Allentown, Philadelphia, Trenton, and Wilmington all topped 90°F Thursday, with Atlantic City Marina still holding out after a record 1,064-day stretch below 90°. For most remaining stations, the next chance at 90° is expected by Thursday, June 20.
Philadelphia’s first 90° day came later than any year since 2014. In contrast, Atlantic City International Airport spiked to 96°F—tying its June 12 record high from 2017. Wilmington and Georgetown also reached 94° and 91°, respectively, with heat indices near 100° in some inland areas.
Mount Pocono and the Atlantic City Marina remain statistical outliers. The Marina’s current 1,064-day streak without a 90° day is its second-longest on record, trailing only a stretch from the late 1800s.
More heat is likely ahead. Residents should stay hydrated, limit outdoor activity during peak afternoon hours, and check on vulnerable neighbors as summer conditions settle in.
