September is a great time to visit. Best weather for the towns on the bay.
What are your interests ? Sight seeing, food, museums ?
Got a masters degree from Berkeley in the early 70s and have lived in Marin County since.
The campus is in a great location and is an impressive city type school as long as the radicals are not out in force on a protest. Memorial Stadium in Strawberry Canyon is in a spectacular location with great views of San Francisco and the Golden Gate. There is an on campus art museum and Oakland has a California history museums.
If the outdoors is of interest , Tilden Park in the Berkeley hills has miles of hiking trails or Mt Diablo in Walnut Creek. Highest peak in the Bay Area.
There are unique restaurants , starting with Alice Waters' Chez Panisse and several micro breweries