If you miss the flight, you're better off driving up to sac'to as that will be faster than waiting for the connection. It's only a 2-hour drive. If you don't want to drive, you can take Megabus or a bus+train combo.

June is usually pretty bad with fog in the city, so it really depends on the day and on your luck as to whether the fog reaches the airport or not.

Honestly, if you have to pay for the ticket separately, you're better off driving or taking a bus up to sac'to, as the total travel time will be very similar to what you will have with waiting for your connection+flying+getting to your destination in Sac'to.