This week the sunny days will lead to chilly nights unlike the cloudy days and nights we had last week.
The Philadelphia area should be seeing about 10 hours of sunlight for this time of year. The last few days you could have counted the sunshine in minutes instead of hours.
The National Weather Service in Philadelphia ranks the cloud cover each day on a scale of 1 to 10 with 10 being completley overcast. Since the November 3 only nines and 10s have been needed.
Check out the Phildelphia climate page
If you look at the temperatures during those cloudy days, perhaps you noticed this yourself, you will see that there is very little temperature change between the low and the high each day.
Last week there were a few days that the temperature never dropped below 55 degrees. That is quite mild in the morning -- with the clouds it may have only warmed up a few degrees.
The clouds act like a blanket and prevent heat from escaping into space at night, instead the clouds absorb the heat and send some back to the surface. That will not be the case this week.
This week expect clear skies combined with cooler air moving in that will allow the temperature to drop down into the 30s Monday, Tuesday and Wednesday.
So you may have been able to keep the jacket at home last week but keep it handy this week, the morning chill will be back.