yikes i meant spirobulldog sorry.

I am not familiar enough to tell you much about the foggiest times. I think October might be the clearest month, but I'm not certain. Certainly the CA Coast can be foggy. I actually like it to be foggy some of the time as I feel like I've really experienced it and is adds a bit. But, then I like for it to be nice too.
You can't go wrong with San Francisco. I have never really done Napa/Sonoma, as wine isn't really that much of an interest to me, although there is a lot more to do in that area as well. One day isn't much time in San Fran though. You could also go down to Monterey area too.
I've been to Redwoods twice around 1st of June and it wasn't that foggy, just spotty fog. My 2 or 3 trips to San Fran, Point Reyes, Monterey have all been over Spring Break. Have had some fog on all of those trips. Weather is hard to predict. I know I didn't help much, but I would just go with whatever interests you the most. Since you are doing Yosemite, it might be nice to get a day or two at San Francisco for a different experience than nature. But, you really can't go wrong with Point Reyes either. If I had never been to SF, then I would probably spend some time there.

Thanks spirobulldog. I've been to San Fran several times but my daughter has not. That's why we will plan just a day there. I know it's not much but at least she will get a feel for it. This trip is really about Yosemite and something additional. When you went to Pt Reyes, did you stay up there , or just do a day trip from San Fran. So many nice places to see! thanks for your quick response.

Not quite sure why you are specifically asking a Sooner about fog in CA (though spirobulldog does post lots of really good info about the West)

June can be cool/cold/foggy/warm on the coast. Cool/foggy is most likely. Often the fog does clear by noon/early afternoon, only to roll in again mid/late afternoon - but not always. Inland (Napa/Yosemite/most anyplace inland) can be absolutely beautiful or bloody hot. It can be 100F in the Central Valley and 50 miles west on the coast or in SF it can be 60F and fogged in.

Its called June Gloom

I have a roadster -- I would plan my top down, coastal road trips in Sept - not June.

I didn't stay at Point Reyes, just did it as a day trip. If I were to do it again, I think I would stay there. It is a bit more of a drive than I anticipated. We stopped at Muir Woods for a couple of hours too. Plus, there really is a lot to see and do there-depending on how ambitious and hiking you want to do. If you really like hiking, then stay at Yosemite another day or two or three. I really want to go back to Yosemite.

Not just June for fog--maybe down the coast in Southern California it's only June. In fact I don't recall any long time residents of SF talking about June gloom, we just call it summer!!!

(Yes - you can tell all the summer tourists in SF by the brand new sweatshirts and blue knees)

I'm going to take a bit and plan the rest of the trip. I'm thinking Sonoma, Napa maybe Calistoga. Thanks for all you opinions and suggestions.

Now we are planning on coming from Yosemite and staying in Murphys for one night as suggested in another thread. It should be a 2.5 hour ride to the Napa Sonoma area where we can stay for 2 nights.
Now I just need to figure out where to stay, particularly on our last night in San Francisco. We have a early morning flight home and I am thinking of staying in a Marriott in San Francisco and just getting up early. Does anyone have any thoughts on this? I'd appreciate it. thanks

Personally, I'd stay at the airport. It's just an extra half-hour, though, from the city. Will you be parking a car/driving to the airport? I think it would be easier to return the car the night before, take a shuttle to your hotel and back to the airport, otherwise, you'll need a lot of extra time in the morning. There are plenty of airport hotel choices, including a Marriott.

I agree with sf7307 about making life easier by staying at the airport.

You can do things off the airport until after dinner (I think there are some intersting Asian places in San Bruno), then drop your wife/husband/family/party and luggage at the hotel and return the car. You can then take the tram and shuttle back to the hotel yourself, luggage free.

I have stayed in the city, stayed in Oakland, stayed in Berkeley, and stayed at SFO, all for planes from SFO. All these worked, but I would be especially inclined to stay at the airport on a work day.