Philadelphia hit 91 degrees at Philadelphia International Airport on Thursday afternoon, breaking the city’s April 16 record of 90 degrees set in 2002. It was the second record day in a row after Wednesday’s high, and the city also did not fall below 65 degrees Thursday morning, setting a record for the warmest minimum for the date.
For Ruth McDermott-Levy, the swing was hard to dress for. “I mean, I don’t know how to dress,” she said, before adding that the stretch felt like “a sort of spring training for the inevitable summer heat to come.”
The reading landed in the middle of one of Philadelphia’s warmest April runs in 150 years of official government records, and it came after a memorable winter. That same morning, the U.S. Drought Monitor showed the entire region in moderate drought, after Philadelphia had logged below-normal rainfall for seven consecutive months.
The heat is not expected to stick around. Friday’s high was projected in the low 80s, then a backdoor front was due to cross the region Saturday and bring a potent sea breeze, according to the National Weather Service office in Mount Holly. Sea-surface temperatures in the nearby Atlantic Ocean were still only in the upper 40s to upper 50s on Thursday morning, a reminder of how quickly the air mass can change once the coastal breeze turns.
Tom Kines said the pattern fits April. “It is hard to sustain a warm spell in April,” he said. “A lot of times there’s an opportunity, and it just doesn’t happen.” By Sunday, highs could be as much as 30 degrees lower than Thursday’s, and the grasses and plants may get as much as a half inch of rain.
The bigger concern may be what follows. The weather service might post frost advisories for Monday morning, when lows could drop into the upper 30s, and freeze warnings could be posted for parts of the region for Tuesday morning as temperatures tumble deeper into the 30s. Paul Pastelok said dryness can amplify later-season heat, noting that “what can drive any heat the rest of spring and early summer is the dryness of the ground.” For Philadelphia, the immediate answer is a sharp fall from record warmth to cold enough to threaten frost in less than five days.
