Spring is off to a cold start in the Philadelphia area.
Winter officially turned to spring on Wednesday, but temperatures over the last week have been solidly below average.
Normal high temperatures for mid-to-late March are in the low- to mid-50s. But some days, the high has barely passed 40 degrees.
On Thursday, the high was just 40 degrees -- 14 degrees below the average high of 54, according to the National Weather Service. March 18 saw a high of 42 degrees, and March 17's high was 43.
Low temperatures have also been colder than normal. Today, for instance, the normal low is 36 degrees. But the temperature dropped to just 28 overnight.
Typical lows for this time are between 34 and 36 degrees. Low temperatures over the last week, though, have generally been below that. Thursday saw a low of 30 degrees and the temperature also dropped into the 20s on March 15, when a low of 29 was recorded.
So what's behind the cold stretch?
"There's a very deep low pressure system north of Nova Scotia," said Mark DeLisa, a National Weather Service meteorologist. "The flow around it is bringing down cold air from Canada."
Though the past week hasn't felt particularly spring-like, March as a whole hasn't been particularly cold.
"The average for March is only a degree below normal," DeLisa said. "Through the 13th, March was above normal."
But the weather service is calling for the cold to continue. The service doesn't predict the high temperature to top 49 degrees in the next week. And there's a possibility of snow Sunday night into Monday.
From 2 a.m. Sunday through 2 p.m. Monday, there's a 60 percent chance of snow, the weather service says.