As of 3 p.m., show had already started falling in Chester and Delaware Counties, signaling a possibly messy homebound commute for Philadelphia area drivers.
Up to three inches could fall around the region, with one to two inches most likely, the National Weather Service predicts.
The heaviest snowfall will come in the late afternoon and evening, and should taper off around midnight, according to the National Weather Service.
This week's bitter-cold temperatures make snowfall more hazardous.
"The snow will accumulate immediately," an advisory said. That means slick travel conditions could develop quickly.
"Be prepared for slippery roads and limited visibilities," the weather service said.
The 23 degrees recorded about 2 p.m. is likely to be the high in the city today.
Philadelphians who have grown tired of this week's cold stretch -- the mercury hasn't risen above 27 dgrees since Monday -- can be encouraged by next week's forecast.
On Tuesday, the weater service says, the area can expect a high of 49 degrees. And for Wednesday, the service is predicting low 50s for the region.