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After record-breaking heat, Philadelphia temperatures plunge into a freeze warning this week

April temperatures continue to swing from extreme heat to freezing.

Parent spectators Julie and Dave Sun (right) of McLean, Virginia have their own personal shelter from the rain, among the school tents along the bank of the Schuylkill Sunday, April 19, 2026, during the 5th of the spring series Manny Flick / Horvat regattas.
Parent spectators Julie and Dave Sun (right) of McLean, Virginia have their own personal shelter from the rain, among the school tents along the bank of the Schuylkill Sunday, April 19, 2026, during the 5th of the spring series Manny Flick / Horvat regattas.Read moreTom Gralish / Staff Photographer

Button up, Philadelphia, the temperatures are set to drop significantly this week with a freeze watch issued for Monday night into Tuesday morning.

After a week of record-breaking heat with 90-degree days, the weather cooled significantly over the weekend, concluding with a mostly overcast Sunday that brought light rain and wind gusts as high as 25 mph to the region.

On Sunday, the National Weather Service issued a freeze watch for Philadelphia and Delaware Counties, as well as New Castle County in Delaware, in effect from late Monday night through Tuesday morning. The agency expects subfreezing temperatures on Monday night as low as 27 degrees, which could negatively impact crops, outdoor vegetation, and plants, and potentially damage outdoor plumbing if not properly protected.

This move back to chilly weather follows a month of spring swings in temperature. April began with record-setting heat, and by the second week, a freeze warning was in effect that impacted cherry blossoms and other local blooms.

The unusual heat in April is due to lower than normal rainfall in Philadelphia — and a monthslong drought in New Jersey — coinciding with the lack of shade, as trees are still regrowing their leaves. The highs on Wednesday and Thursday last week were roughly 25 degrees higher than normal for previously recorded dates, though historically it’s not unusual for the region to see 90-degree days in April.

The abrupt changes in weather don’t mean too much for predicting summer conditions, but some may see the recent temperature spikes as opportunities to prepare for the impending Philly heat. As Inquirer weather reporter Tony Wood summed it up last week: “April is a month for all seasons.”