The sudden cold snap that hit Pennsylvania over the weekend was a little late but not unprecedented, according to forecasters.
Aaron Tyburski, a forecaster with the National Weather Service in State College, said the weekend cold snap came from an Arctic high pressure system that came down from Canada, and light winds and clear skies helped temperatures to cool off in the evening.
Temperatures dropped to 38 degrees Monday morning in Philadelphia and 31 on Sunday morning in Pittsburgh.
In some parts of the state, frost can hit in virtually any month of the year, Tyburski noted. For example, in Bradford, in the northwest, the latest recorded spring frost was July 12.
The earliest fall frost there? Aug. 3, though in a different year.
Paul Knight, Pennsylvania’s state climatologist, noted that in recent decades temperatures here have warmed, resulting in a growing season that has expanded by one to three weeks in different regions over the last 30 years. The growing season is the number of days between the first and last frost.
The weather service predicts that temperatures across much of the state will rise slightly this week, with lows in the 30s and 40s and highs in the 50s or low 60s.
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