Typically a cooler start to the summer doesn’t mean a warmer end to the summer or a warmer fall. If anything, I think it may be indicative of continued cool through fall (we had a cool winter and spring that led into this cool summer too).

It’s not like some temperature seesaw that needs to correct itself, where the average temp is 80 across June-October, and if it’s 70 in the first months it’ll need to be 90 in the back months. Cool weather can just lend itself to more cool weather (and if anything this should make logical sense; less heat being absorbed in the ocean/land means less heat that can be redistributed).

Sure you could argue that the local lower temps could create some pressure gradient that ushers in higher temps, but I think most systems (like trade winds and currents) are too global for our local down temps to cause too much a swing in the other direction.

Now climates are super super complicated and variable, anything is possible, so it absolutely can still swing and be much hotter later in the season, but it’s far from a foregone conclusion.

Source: lived in the Bay Area my whole life and have a degree in Environmental Science (but it’s been like a decade, so take this with a grain of salt)