Early birds were scraping frost off their car windows this morning, heading into a weekend that will see the coldest temperatures since March in Philadelphia.

Enjoy today's high of 50 - it might be the warmest temperature in the city for a week.

And the suburbs tend to be colder.

This morning saw the upper 20s all around the region, except at Philadelphia International Airport, where the low reached the freezing mark.

To keep things in perspective, though, that's normal for this date. The city's record low for Dec. 9 is 6, set in 1876.

It may seem extra cold because it's been unseasonably warm.

So far this winter at Philly International - the National Weather Service's official yardstick for the region - only Halloween fell below freezing.

But that's about to change.

Tonight won't be as cold - the low should be in the mid 30s - but Saturday and Sunday nights should see temperatures in the upper 20s in the city and its South Jersey suburbs, the low to mid 20s in the burbs on the Pennsylvania side.

Saturday is likely to feel chilliest, because it's expected to be breezy.

Welcome to the return of windchill weather.

The last time Philly International saw the upper 20s was late in March.

The highs also will be low. Sunday's forecast high of 41 is the chilliest since a high of 36 on March 3.

But, technically, it's not even winter yet. That starts Dec. 22. So you know worse is on the way.

Last January, which was colder than February, the average low was 23.

Monday to Thursday, the lows should moderate into the 30s while the highs remain in the 40s.

No rain or snow is mentioned in the weather service's seven-day forecast, but Weather.com suggests possible showers Thursday.

Contact staff writer Peter Mucha at 215-854-4342 or pmucha@phillynews.com.