Monday's temperature shot up to 43 degrees around 3:30 p.m., but with the wind, wind chill sat at 35 for most of the day.
With clear skies, low humidity, and decreasing winds, temperatures will drop to the lowest levels of the season so far, ranging from 21 degrees in the coldest suburbs to 29 degrees in Philly.
The warming-up begins Tuesday, and will peak Friday, when some record-high temperatures are possible.
Then a cold front will move through the area early Saturday, lowering temperatures to near average. Some showers are possible with the cold front.
Monday: Clear, but then clouds increase. Low of 29 in Philly, low of 21 in the North and West.
Tuesday: mostly sunny and chilly with a high of 49.
Wednesday: sunny and cool with a high of 52.
Thanksgiving: sunny and warmer with a high of 62.
Friday: mostly sunny and warm with a high of 67.
Saturday: showers, then windy and cooler with temperatures dropping into the 40s.
Sunday: mostly sunny with a high of 50.