I heard most of the city used to be very foggy for months on end. But now most of the city is sunny all year round before noon till early afternoon (about 11am-3pm) except maybe parts of outer sunset and outer richmond. In Bayview, fog doesn't even usually roll in until after 10pm (except in July)
This is true. I've lived in the Bay Area since '05, and have met many people who were there since the 80's and 90's. Actually, I think most of them have left. But by the mid 2010's, many of them would comment on how unusual it was that the fog just wasn't rolling in anymore.
One person I knew was sensitive to certain allergies that would become markedly worse without the fog. So she knew.
It isn't just SF proper. Along the peninsula, on Highway 35, the fog used to be so thick you couldn't see more than 30 ft in front of you – maybe even 10 ft some days, and especially in the evening. I lived in those mountains around the 2006-2007 timeframe, and it was fun to drive down the 35 by memory (at least if you were an indestructible-feeling 20-something), since it wasn't possible to see down the road for any safe distance. Nowadays, there might be fog, but it's invariably "safe."
Another bit of history. The first navigators kept passing by the bay for years because they could not see the bay from the sea due to the fog. This is why people settled in SF later than in other places in the region. So, the fog was probably damn thick at the time.
I lived in SF from 1989 to 2006. In the summer, downtown was usually sunny during the day while sunset and richmond were socked in. Fog moved further in towards the afternoon/evening. I lived in the sunset and richmond the whole time and didn't see any change. In 1989 I sometimes didn't see the sun for weeks and 2006 still didn't see the sun for weeks, in those districts. Maybe something has changed in the last 15 years?
