California doesn't have a statewide ban on personal vaping. But that doesn't mean you're clear everywhere. Cities and counties can pass their own restrictions, and many have. San Francisco famously banned flavored tobacco products, and several other cities have followed with similar measures. Public vaping is often restricted too—some places treat it like smoking, so you'll need to step away from doorways and outdoor dining areas.

Before you go, look up the specific rules for each city you'll visit. The California Department of Public Health has a page on tobacco control that links to local ordinances. It's not the most exciting reading, but it's better than getting a fine or having your device confiscated.

Also, check whether the place you're staying—hotel, Airbnb, whatever—has its own policy. Many have banned vaping indoors entirely.