I've checked the long range forecast but was still wondering how cool it gets in S.F. during early August. Is a leather jacket overkill or will a lighter coat be better?
Are jeans OK in most casual restaurants or are khakis better? Any thoughts will be appreciated.

I assume by SF you mean South Florida. If you do, Are you Kidding? Leather. It is Hot Hot Hot. I live here for 30 years. Aug and Sept. are the hottest months. Unless you are going to South Beach and want to make a fashion statement leave it home. Unless it is a fancy, schmancy restaurant jackets not required. I think khakies rather then jeans. The further you get out of most large areas shorts are acceptable in places. Remember tourists are not the best dressed. Evenings will definately bemid to upper 70's and days upwards to in in the 90's. But Humid, humid, humid. Any other questions you can EMail me.

Its been fairly cool here ,a little more so than normal. Low to mid 50's with substantial fog at night , a range in the 60's during the day with fog burning off sometime in the afternoon. This is very changeable though and you could see temps in the 70's or even up into the 90's. You really have to come here prepared for everything and that might take place within the same day. Hence the "layering" mantra. I'd probably go with a light jacket over a sweater or sweatshirt so you can adjust as needed. There is a fairly wide range of clothing here and a good pair of jeans are fine in casual places. There are those who dress up a bit but wear whats comfortable for you, you won't stick out. You might want to look at http://www.sanfrancisco.sidewalk.com for visitor information. Check something like usatoday.com for 5 day forcast before you come but understand these a notoriously iffy and temps can change drastically here , acouple of days in the 90's and then 60. LAYER.

Sandy,
Sorry for the confusing abbreviation. I meant San Francisco, not, South Florida.

No confusion here. I believe that 90% of people know that SF is a common acronym for San Francisco. Layering is the key to everything in San Francisco. This is especially true if you intend to visit other places in the SF Bay area. 5 miles can result in a 25+ degree temperature change. From your e-mail, I assume that you are from Atlanta. If so then you will most certainly find it pretty cool unless we have one of rare hot spells. Those are more common in September. I would probably not bring the leather jacket but sweaters and light jackets are fine.

Jeans will be fine in almost all restaurants.

Agree with above. Don't think it's quite leather jacket time! Cotton sweaters, sweatshirts, windbreakers, summer "dress" jackets. SF is a bit dressier than other U.S. cities and a bit more conservative, but jeans are OK for almost everywhere. Keep checking that weather forcast--right up to the day of departure, but you will want something for when the fog rolls in.

Having been born in Palo Alto, I learned about the SF fog and July temperatures early on. If the fog is rolling in, SF can be downright chilly. Ever get a look at the way the spectators are dressed at night baseball games at Candlestick Park (or whatever they call that stadium these days)? Insulated headgear, down filled parkas, gloves -- they could equally be at a Packers home game. But if the sun is brightly shining, you can be quite warm. It all depends on the fog. Mark Twain wasn't kidding when he said that the coldest winter he ever spent was one summer in San Francisco.
The last time I was there, I rode the cable cars dressed in a light weight down filled jacket. Then we drove south of Palo Also and it was 90 degrees.

We have just returned from San Francisco. My husband loves the city. I must admit that although I thought I was prepared. I was not! It was much colder that I thought it would be. I really saw people with gloves, hats, winter jackets and to be fair I wished I had brought them. We spent three days in Nappa and Sanoma before arriving in S.F. It was thrity degrees difference.
They are approximately one hour driving time from downtown S.F. I felt like we have left one world and driven into another. I would take at least layers that you can be comfortable and warm. Jerseys and sweatshirts, etc. I, too, believe S.F. is a bit dressier however, I was so cold when I left my hotel, I didn't care. I also did not have the appropriate clothing. Anything that was
was not at all warm enough.
I would suggest warm and comfortable! See the wine country if possible, it was wonderful!