[header] How to travel from san francisco to napa valley [title] Leave before or after rush hour on a weekday. [step] Traffic in san francisco can be pretty bad at peak times, so try to plan your departure around it. To do that, you'll want to leave very early-around 6:00 am-or later, between 10:00 am and 3:00 pm. 
[substeps] There might be traffic on the weekends as well, but it will be harder to predict. Check for real-time traffic reports online or tune into a tv or radio station report for an update before you leave.