I'm hoping that Stu or one of the other locals who give such great advice can let me know about the fog situation in May. We are making a trip to Yosemite at the end of May and have one and a half days in San Francisco. I know, not nearly enough but I want to make the most of it. I've been before but DH has not. I would like to take a bus tour and he wants to see Alcatraz. From what I have read, summer fog comes in the afternoon. What about May? Thanks so much!

Not to worry. If any fog it will not be a detriment to your trip. I'm sure you will have a fabulous time!

This is not going to be a concern, and I don't know of any regular afternoon fog at any time of year.

May can be great weather and is one of the months before the fog gets bad. June Gloom comes to mind.

However, generally if there is fog it will usually burn off by mid day - and if it is an unlucky day it will be foggy all day.

On days when it begins clear and "hot" then the fog may roll in later in the day as things cool down. I always think of it as a pendulum - really nice for a few days and then the fog returns, gets bad for a few days, then it clears off more and more, then it is really nice and gets warm again...repeat

The fog is usually in June, July and August. It is caused by the heat from the Central Valley doing something I don't understand and pulling in moisture from the ocean. If there is fog it is usually in the morning and, as someone said, burns off by noon. But I don't think you should worry about May.

Well - our electricity has finally returned after being out most of the day. Quite a storm we had (still have).

Like others have said, not that much fog in May, and it's almost always in the mnorning - not mid-day or in the early evening (can return in the late evening).

Stu Dudley

Thanks everyone. Stu, glad to hear that your electricity is back on. We were watching the terrible weather last night. The only positive thing that I could think of was that with the rain turning to snow in the mountains, the waterfalls should be good this year. Everyone in the area take care!

One of the unique things about the Bay Area are the various micro-climates. It can be 80 degrees 15 miles away from SF and 50 degrees in SF.

Moreover, there are differences in different parts of San Francisco itself. It is mostly foggy in the Sunset and Richmond Districts (Golden Gate Park) and more sunny in the Mission, Downtown, Chinatown, and Noe Valley. Golden Gate Bridge is always cold. Have fun in the City. It's a GREAT place.

Hello seashell,

The prior posters have given you a good picture of the foggy season and its quirks. There might be fog that lasts all day, there might not. May is not in the real "fog season" yet, because it's usually not hot enough in the central part of the state to start the whole interior-coastal push-pull climate thing going. However, if there is fog on the day you go to Alcatraz, it could actually make your trip more dramatic - there could be a layer of fog low on the water with a view of the City rising above it in bright sunlight, or there could be a bank of fog pulsating like a moving mountain range just beyond the Golden Gate. Don't worry - enjoy what happens - it'll be a great trip.