Public wi-fi is never safe no matter where you are using it from. Usually, restaurants and coffee shops such as starbucks have a public wifi for its users to use while they dine in. In fact, places like starbucks are the second home for most university students and those who freelance. These public wi-fis can easily exchange your information and your data will always be at risk for as long as you are connected with them.
This is because public networks do not keep information private as much as personal internet connections do because of higher security. Hence, you should avoid public connections as much as possible.