Whale watching season in San Francisco Bay, it's not Hawaii but it's a fun San Francisco attraction. I took a whale watching cruises in December 2009 with my husband for his birthday.
We took the cruise with San Francisco Whale Tours. They are a good company and did a great job. I saw a whale for just a second and the spray from a blowhole and my husband missed them entirely! But it's not to say that I wouldn't go again.
I learned the seasons for the different whales along the Pacific Ocean near San Francisco and the bay.

Gray whales - migrate through the bay area from around Christmas through May.
Gray whales that are males can grow to 40 feet and females to 42 feet. They are obviously mostly gray but have white patches that scientist use to identify them individually. They migrate between Baja California and the Arctic each year.

Humpback whales are around the off shores of the San Francisco Bay throughout the year.
They have very long flippers. The males are about 48 feet in length and the females are even longer. Almost entirely black but they do have white on their flippers and undersides. They are different in their own different tail patterns on their tale flukes. When they migrate they swim in pods of three or four.

Blue whales - they are offshore year round but typically seen from early summer through fall.
Blue whales are the largest animals ever to known have existed. They can be 108 feet in length and more than 190 tons in weight! They are various shades of bluish-grey and lighter on their bellies.
It's not
really known how many of them there are in the world today.
Whale watching season in San Francisco is basically year round.
Whale watching in San Francisco is something I had never done even though I have lived in the Bay Area for 30+ years. I'm so glad I went and I will do it again because whale watching in San Francisco is one of those fun San Francisco things to do I just have to keep doing again!