Here you go.
It was high 20's to low 30's most of last week. Not sweatpants and sweatshirt weather. IMO
It was 38c on Monday...Yikes!!
http://www.wunderground.com/history/airport/KFAT/2009/8/13/MonthlyHistory.html#calendar
Quoting myself because I made an error. For some odd reason I put in Fresno and not Oakland.
The temps for Oakland are in the link below.
Last weeks temps were low 20's and on Mon Aug 10 it was 28c. I guess if you feel the cold you may wear a sweater and sweatpants.
http://www.wunderground.com/history/airport/KOAK/2009/8/13/MonthlyHistory.html#calendar
Sorry for the confusion.